# How To Find Acceleration In A Pulley System With Friction

Treating the pulley as a uniform disk, find the downward acceleration of the weight and the tension in the cable. Select mechanical drive mechanism to be used and calculated inertia, friction and load torque using formulas provided in this document. First we will measure the acceleration and tension in the inclined plane conﬁguration and then measure the acceleration of an Atwood machine. suppose you. The coefficient of kinetic friction between this mass and the plane is 0. In our calculations, we sum the moments around the pulley axle, having determined the tensions in the cables, to find the value of the force of friction on the pulley. 20 between the block and table. • Prepare the system as in Figure 2. The relationship between the tensions in the tight and loose branches conforms to the Euler equation. However, T 0 can be thought of as the tension required to cause the cart to move with zero acceleration, that is, the tension required to overcome kinetic friction. coefficient of kinetic friction between box A and the table is 0. The system is then released from rest. calculation of acceleration 'a' calculation of tension 'T' Example. Find acceleration, tension & kinetic friction given mass and coefficient? A rectangular block of wood (block A) with a mass of 8 kg on the horizontal table is attached to a pulley. All you need to know is that speed is expressed in feet per second (imperial/US system) or in meters per second (SI system) and time in seconds. (2) and the experimental acceleration from eq. smooth pulley at the end of the table. 0 Facts about pulley-belt system Figure 3 below is a schematic of a pulley-belt system. Systems of Blocks and Pulleys 1. 10Nm calculate the (a) angular acceleration of the pulley. Of course, a and T are the same in both of these equations. By carefully choosing the right pulley size and configurations, we can change displacement, speed and acceleration of a pulley-belt system. Shows how to calculate the acceleration of a two block system with friction using Newton's Second Law. In other words: F f = F N Where is a constant called the coefficient of kinetic friction. Apparatus: computer, low-friction smart cart, two track supports, two cart stoppers, massescart (four 250 g), track, pulley, string, 5 g mass hanger, and masses (one 10 g and one 20 g) Part A: Identifying Forces and Making Predictions. The coefficient of static friction is μs, between block and surface. Physical picture: In the Atwood’s machine, the tension force pulling on the heavier mass M is larger than that pulling on the lighter mass m. Choose the other axis perpendicular to the first. $W_{A}=mg=(8. Given: since the force of 10N was applied when the body was just about to move, then the static or limiting frictional force, F = 10N. Newton's second law says: Where F net is the total force an object, m is the mass and a the acceleration. Note: gas pressure can be converted to head using:Gas head = gas pressure ÷ (liquid density x acceleration due to gravity) Pump Suction Frictional Head Losses. 25 for both blocks, find: a. T = m(g-a) (5) There is some friction in the bearings of the rotation apparatus. Since they act against each other the net torque equation would appear as: t net. Find their acceleration and the tension in the rope. 3 the blocks are released from rest using energy methods find the speed of the upper block when it has moved 0. Systems of Blocks and Pulleys 1. Procedure The way to test this theory is to apply a force to an object and measure its acceleration. There will be a second rope that loops around the pulley and is attached on one end to something static and rigid and the other end us attached to something that is creating a force like a block that is dropping straight down. Frankly, we were many years ahead of CEMA on pulley shaft design. suppose you. The coefficient of kinetic friction is 0. It depends. Pulley + Spring combinations – In the third group, our review deals with systems where spring(s) are added to pulleys. Apparatus: PC, photogate/pulley system, wood block, mass set, mass hanger, string, and balance. 47, and makes an angle of 20. 600 Correct Lifting a Bucket A 6-bucket of water is being pulled straight up by a string at a constant speed. A block of mass m slides without friction down the wedge (Figure 8. A smooth pulley is fixed at the vertex of the skeleton. Last Revised on January 8, 2015 Grade: _____ Experiment 2 Acceleration of Gravity 1. (c) Find the linear acceleration of the airplane tangent to its flight path. This illustrates that greater force is required to move an object of a larger mass. The gravitational acceleration n is a constant equal to 9. A fixed (attached to a non-moving object) pulley changes the direction but not magnitude. 25 kg the acceleration now? 2. Theory: A block of wood resting on an incline at some angle θ is being pulled up by a string at. 0ms and the acceleration of the blocks is constant. Answer (1 of 1): Since there's no friction then the Pulley will not rotate as the torques due to tension cancels out. Finding acceleration of blocks in a pulley system. When in motion, each particle is subject to a constant air resistance of 3. Problem Restatement. The friction developed on either side of the pulley across the string contact can also be ignored, again due to its negligible occurrence. So substituting: 50 - 2 = 4 x a. The goal of the problem is to calculate the accelerations of blocks 1 and 2. a Modelling the floor as smooth and the load as a particle, calculate the acceleration of the load. 385kg m² respectively. 0 Facts about pulley-belt system Figure 3 below is a schematic of a pulley-belt system. CycleTrader. Calculations include conveyor capacity, belt speed, conveyor height and length, mass of idlers and idler spacing, belt tension, load due to belt, inclination angle of the conveyor, coefficient of friction, power at the drive pulley, starting belt tension, acceleration of the conveyor belt, and belt breaking strength, all with descriptions of. Angular Vector forces can be calculated using mathematical formula. (Look up 'Inertia Transfer Formula', or 'Parallel Axis Theorum') An alternative would be to draw the drum in a 3d cad program (solidworks, inventor, etc) and then tweak the material density until the inertia matches the catalog value. (a) Assuming the kinetic coefficient of friction between steel and stone is 0. The Atwood machine (or Atwood's machine) was invented in 1784 by the English mathematician George Atwood as a laboratory experiment to verify the mechanical laws of motion with constant acceleration. Therefore, we calculate the acceleration component. By graphing the acceleration versus sinθ, the acceleration due to gravity can be determined. advantage of a pulley system can be determined experimentally. Frictional. If you already know how to calculate acceleration let's focus on the units of acceleration. pulley system on a double inclined plane Note that each line corresponds to a particular value of friction coefficient. Readjust the pulley so that the cord is again parallel to the plane. We have to find the normal force a small section of rope exerts on the cylinder. Friction always opposes the direction of motion. 8 A woman is trying to push a load of mass 50 kg across a floor. For each run, calculate v 1 and v 2 from eq. The coefficient of kinetic friction is μ k = 0. What I did was I used two different weights and found the acceleration of the lighter weight going up the pulley. It is important to remember that NO pulley system is 100% efficient. Find the value of m necessary to cause the block to slide at constant speed. The new, compact system is incredibly lightweight, weighing only 9kg/19. • This is an example of static equilibrium. 2 m/s up aB = 3 m/s 2 down 23. Place wood stopper block in front of pulley to stop the cart from smashing it. Loosen the thumb screw to unlock the swivel mount and adjust the position of the smart pulley. The bottom pulley and mass M have the same acceleration. We have to find the normal force a small section of rope exerts on the cylinder. Find the acceleration and the tension in the rope of the system of masses shown (M > m), neglecting the mass of the string and the inertia of the pulley assume that the static and kinetic friction coefficients are equal to μ 1 μ 2 and the slope angle θ are known. The box has a mass of 75. Our lab uses the force of gravity in order to find the maximum static friction force on an object before it turns into kinetic friction. The Atwood Machine is a coupled system of two weights sharing a connecting string over a pulley. Assumption 2: The acceleration of both masses is equal. Ignore the mass of the cord and pulley and any friction in the pulley. The front half of the rear pulley is placed under pressure by the contra spring to make sure that it holds the correct tension to ensure the best gearing. 0 Facts about pulley-belt system Figure 3 below is a schematic of a pulley-belt system. Select mechanical drive mechanism to be used and calculated inertia, friction and load torque using formulas provided in this document. I predict that as the number of pulleys we use increases, the effort needed to lift the pulley will decrease. F equals ma is the mathematical expression of Newton's second law. My Solar System: Friction: Lunar Lander: Forces in 1 Dimension: Maze Game: Ladybug Motion 2D: Calculus Grapher: Gravity Force Lab: Motion in 2D: The Ramp: Forces and Motion: Ramp: Forces and Motion: Buoyancy. Using this set up we can find out the acceleration of the suspending object and the tension of the string using equations. A pulley is nothing but a wheel which is kept on an axle with a support of a string or wire. Calculate the force caused by gravity on the basic pulley system using the following equation: G(1) = M(1) x n and G(2) = M(2) x n. - RAY 213613P online from NAPA Auto Parts Stores. The heavier weight pulls on the lighter causing both to accelerate in one direction with a common acceleration. When we want to calculate the force, and we have the mass and acceleration, we can simply use the simple formula stated in the Newton's second law above, that is =, where is the mass (or the amount of matter in a body), and is the acceleration. There will be a second rope that loops around the pulley and is attached on one end to something static and rigid and the other end us attached to something that is creating a force like a block that is dropping straight down. Seamless Torque Transfer – CVTF Type N3 maintains exact lubricant thickness in the belt and gear system in JATCO CVT 7 and maintains precise distance between the steel belt and the pulley in JATCO CVT 8, meeting the required friction reduction performance for continuously adjusting gear ratio to provide seamless torque transfer from the. To calculate the pressure drop and flowrates in a section of uniform pipe running from Point A to Point B, enter the parameters below. If you're seeing this message, it means we're having trouble loading external resources on our website. Calculate the value of T 1 and T 2. Lab 2 Force and Acceleration - Newton's Second Law Objective: < To observe the relationship between force and acceleration and to test the hypothesis that the force is equal to the mass times the acceleration (Newton's Second Law). The box is replaced by a particle represented as a dot. It is attached by a rope over a pulley to a mass of kg which hangs vertically. Problem Restatement. Assume that there is no friction in the given problem. Of course the system is not going to move with acceleration of 9. Use g = 10 m/s2. Find acceleration, tension & kinetic friction given mass and coefficient? A rectangular block of wood (block A) with a mass of 8 kg on the horizontal table is attached to a pulley. The coefficient of kinetic friction between the table and block 1 is a) Assuming that block 1 is sliding to the right (toward the pulley), find the acceleration of block 1. Determine the tension in each part of the belt if the belt is not to slip and: the system uses a flat belt the system uses a V-belt with a 38o V and the same coefficient of friction 40o 60o. Calculate the coefficient of static friction between the body and the plane. In the past, we assumed that the cart rolled and the pulley rotated without friction. • a) Find the magnitude of the acceleration of the block. These mathematical models of tendon-sheath system and cable-pulley system are mainly built by well-known classical Capstan equation, where the radius of the cable is neglected and the cable is considered as perfectly flexible material. In a figure two blocks of masses 2. The only two variables in this system system that we will control are the the two masses. 2 Apparatus Balance, ball bearing, clamps, electric timers, meter stick, paper strips, precision pulley, ramps, weights, metal track. Given an incline with angle degrees which has a mass of kg placed upon it. We will use a smart-pulley attached to a CBL to determine the acceleration of the object. Horizontal Pulley with Friction Application of Newton's second law to a horizontal pulley. Find the acceleration of the system. Calculate the coefficient of static friction between the body and the plane. Now if the pulley is not frictionless (there is friction between the pulley and the cord), then the man must apply a greater force in order to support the box (because you are supporting the box and some of your force is dissipated due to friction) (the system here is also in equilibrium). Calculate (a) the acceleration of C mass m (b) the tension in the string PQ and (c) force exerted by the clamp on the pulley C. When the masses are unequal, the system will accelerate in the direction of the heavier mass. (a) Show that the initial acceleration of the system is given by g/10(2(sqrt3)-3)ms^-2. Laney Vaughan (Fall 2015). 45 N rightward force on a. Browse Suzuki Motorcycles. If the friction force is not sufficient to drive the load, the model allows slip. Newton's First Law: Consider a body on which no net force acts. In a physics lab, Kate and Rob use a hanging mass and pulley system to exert a 2. The system moves to the right at constant speed. It depends. 1 m and mass M=3 kg. a stretchless, massless cord that passes over a small frictionless pulley. One of the man-shaped dummies used in the above test was strapped in place with a safety belt. Equipment Mobile cart on wheels, pulley and pulley clamp, paper clips, stopwatch. XTRONIC CVT is suitable for 2. So this 4 kg mass will accelerate up the incline parallel to it with an acceleration of 4. will "decelerate" over the floor under the combined action of rolling friction and floor slope. Remove the rubber screw cap on the swivel mount. There will be a second rope that loops around the pulley and is attached on one end to something static and rigid and the other end us attached to something that is creating a force like a block that is dropping straight down. 1 Since the surface is very low friction, it is possible to consider the cart and mass hanger as one system. A bucket with mass m 2 and a block with mass m 1 are hung on a pulley system. Block A has weight 4. In other words: F f = F N Where is a constant called the coefficient of kinetic friction. Assume that the mass and friction of the pulley are negligible. Find (a) the acceleration of the system and (b) the tensions in the cord on the left and in the cord on the right. Note that the tension in the rope is NOT equal to the weight of the hanging mass except in the special case of zero acceleration. Question: How does the pulley affect the total mass and acceleration of the system? 1. Suppose that a box is resting on an inclined plane that is attached via a massless cord and a frictionless pulley to a second box that is resting vertically. Taking downward as the positive direction for the hanging mass, the acceleration will be. 020 [kg] * 9. to consider both objects as a single system. ANSWER: = 0. Then using F = ma we get the acceleration of the whole system. In real situations, there are friction between the string and the pulley. The Photogate/Pulley System uses a photogate head to monitor low-friction pulley rotation, providing a simple, versatile sensor. Just like the simple pulleys, the ropes on both sides of the moving pulley contribute. 4 N$ Always begin with a proper free body diagram. (1) and record these values. In a physics lab, Kate and Rob use a hanging mass and pulley system to exert a 2. Assemble your dynamics cart system as follows, be certain cart does not hit pulley. In particular, she is concerned that the package will be too difficult to handle at the top of the ramp and tells you to calculate its acceleration. The box has a mass of 75. (b) linear acceleration of the bucket. • This is an example of static equilibrium. 45 N rightward force on a 0. If the blocks accelerate with a magnitude of a, then the pulley will experience an angular acceleration of alpha=a/R, since the acceleration of the outer-most part of the pulley is alpha*R. If the total resistance force to the motion of the cart is 0. The relationship between force and energy can be derived from the aforementioned 2nd law: So we have first F =m a (Newton's 2nd law) where F is force, m is mass, and a is acceleration. The angle of the incline plane is given, and the coefficient of kinetic friction between mass and the incline plane is. It is important to remember that NO pulley system is 100% efficient. 0 kg, and the system begins to move just after it is released. Worked example 8. calculate the average deceleration of the car over the 0. to consider both objects as a single system. Newton’s second law of motion pertains to the behavior of objects for which all existing forces are not balanced. The objects are initially held at rest. 20, calculate the angular acceleration of the grindstone. The rotating mass eventually either returns energy to the system in a useful way, or something converts the stored energy to some other form of unwanted energy. Assume that the cable does not slip with respect to the pulley. Then, push it a little and make sure that it slides without friction (at constant velocity) on the track. AP Physics 1 Investigation 2: Newton’s Second Law What factors affect the acceleration of a system? Central Challenge In this lab students investigate how the acceleration of an object is related to its mass and the force exerted on the object, and use their experimental results to derive the mathematical form of Newton’s second law. A 730-N force is exerted on the 75-kg crate. Newton’s Second Law of Motion Objectives In this lab you will: • Calculate acceleration by measuring the rate of change of velocity. v Assume the pulleys are massless and frictionless. (Look up 'Inertia Transfer Formula', or 'Parallel Axis Theorum') An alternative would be to draw the drum in a 3d cad program (solidworks, inventor, etc) and then tweak the material density until the inertia matches the catalog value. three of these objects as one system. when and moves upwards (). Quizlet flashcards, activities and games help you improve your grades. More on that soon. The coefficient of friction between the block and the table is \mu= The pulley is frictionless. You can derive them from the equations we listed above. Although Eq. It is not a practical machine. In simple science, though, we tend to use "pulley" just to mean a bunch of wheels and ropes for lifting. Affix a pulley to the shaft of the machine to be driven (see Figure A). ⇒ F =T 1 =T 3 =T 2. What time does it take a box with mass m 1 to go down a distance s on an inclined plane with a slope of angle α when the box is coupled by a rope and a pulley to a bucket with mass m 2? The proportion m 1 /m 2 is such that the box moves down the inclined plane. Theory: The Coefficient of friction is defined as the ratio of force of friction to the normal force, μ = F / N. The particles are released from rest with the string taut. This means that 1 m of rope must come over the pulley and so the load rises 1 m. 8 meters per second 2, so this is about 2. Find the magnitude of the acceleration with which the bucket and the block are moving and the magnitude of the tension force T by which the rope is stressed. Set up the. Pulley + Spring combinations – In the third group, our review deals with systems where spring(s) are added to pulleys. For low contact pressures (normal {perpendicular} force per unit area), friction is directly proportional to the normal force between the two surfaces. (b) linear acceleration of the bucket. 8 A woman is trying to push a load of mass 50 kg across a floor. However, T 0 can be thought of as the tension required to cause the cart to move with zero acceleration, that is, the tension required to overcome kinetic friction. In our calculations, we sum the moments around the pulley axle, having determined the tensions in the cables, to find the value of the force of friction on the pulley. M tot is the total (e ective) mass that is moving, M tot = m h +m car +m pulley. 5 bloch connected to an empty 1. For solving any pulley problem, the first step is to understand the given conditions and write down the constraint equations accordingly. 010 m/s 2 , to assure an almost constant velocity motion. The system is then released from rest. Box B has a mass of 15. suppose you. The string is assumed to be light ( i. It should be noted. FIGURE 2 shows a constant force, F of magnitude 20N pulled a light cord wrapped around a pulley to lift a bucket of mass 1. In real situations, there are friction between the string and the pulley. What is the net force acting on the block?. A rectangular block of wood (block A) with a mass of 8 kg on the horizontal table is attached to a pulley. If we look at pulley system A (Figure 1) and imagine the effort on the right hand rope pulled down 1m. Calculations include conveyor capacity, belt speed, conveyor height and length, mass of idlers and idler spacing, belt tension, load due to belt, inclination angle of the conveyor, coefficient of friction, power at the drive pulley, starting belt tension, acceleration of the conveyor belt, and belt breaking strength, all with descriptions of. Finding fK,BA, the magnitude of the friction force that A exerts on B, will be the simplest, since it has the same magnitude as fK,AB by virtue of the two being Third­Lawspouses. (for pulley) T 2 R - T 1 R - f = I p, (4) where R is the radius of the pulley, f is the fric-tional torque of the pulley bearing, I p is the pul-ley moment of inertia, and is the angular ac-celeration of the pulley. This 9 kg mass will accelerate downward with a magnitude of 4. How to solve a system with Three blocks in a pulley system with kinetic friction constant given. Attach a string to the wooden block, over the pulley and attach a weight hanger to the other end. Block A has weight 4. Is there an advantage in considering the horizontal system in place of Fletcher's Trolley? Yes, because it is easier to find the acceleration for the horizontal system. I have my physics project and need help of calculating the acceleration of the pulley system. If the friction force is not sufficient to drive the load, the model allows slip. Theory: A block of wood resting on an incline at some angle θ is being pulled up by a string at. Calculate the acceleration of the system and the tension in the string. weight - Friction 2. If the Reynolds number > 2320, you have turbulent flow. D) one-fourth of g. 00-kg block is 2. 1 m and mass M=3 kg. The coefficient of kinetic friction between the block and the table is. The Net Force In Figure 4 the cart-hanger system remained at rest because of the brake which exerts a friction force, F f, which changes to. Not sure if I. The hanging mass is 10 kilograms; the mass on the table is 5 kilograms. This example problem shows how to find the acceleration of an Atwood system and the tension in the connecting string. Depending on how quantitative you would like to make the demonstration, you can ignore the mass of the pulley and the friction in the pivot, or you can take them into account by timing the descent of the falling mass, finding the acceleration, and then noting by how much it differs from what you would expect for a massless pulley and. calculation of acceleration 'a' calculation of tension 'T' Example. The acceleration of the two-block system is A) equal to g. The second law states that the acceleration of an object is dependent upon two variables, the net force acting upon the object and the mass of the object. Sometimes i get the right answer when i use just one of the masses to get the acceleration but other times i have to use both masses to get the correct acceleration. The Atwood's Machine is simply a pulley of negligible inertia and friction over which are suspended two masses. Redco™ Nylon is easily machined and is an outlasting, outperforming replacement for tra. Ignore friction and the masses of the pulley and cord. Question: A 9-kg hanging weight is connected by a string over a pulley to a 5-kg block sliding on a flat table. F equals ma is the mathematical expression of Newton's second law. Coupled Blocks - Inertia Example. The coefficients of friction for the red box and the incline are and. Under these circumstances, if you perform a moment balance on a pulley about its axis, you find that, for rotational equilibrium to exist, the tension of the string on one side of the pulley must be equal to the. Consider the mass-pulley system shown in the figure. Example Find the acceleration of an inclined Atwoods machine with a hanging mass of m 1 = 1 kg and a mass of m 2 = 5 kg sitting on an inclined plane which is inclined at 30 o from the horizontal. The moment of inertia is easy to calculate, because we know what the pulley looks like (a solid disk) and we have the mass and radius: The next step is to make the connection between the angular acceleration of the pulley and the acceleration of the two blocks. If we calculate (or just know) the x- and y-components of the net force acting on an object, it is a snap to find the total net force. 7 g's — you'd feel yourself pushed back into your seat with a force about 2. Pulley + Spring combinations – In the third group, our review deals with systems where spring(s) are added to pulleys. 60-kilogram objects as shown and the objects are released, the magnitude of the acceleration of the 0. The car has a string attached to it. A smooth pulley is fixed at the vertex of the skeleton. The Photogate/Pulley System can perform all the functions of the discontinued Smart Pulley. Calculate the acceleration and work done sliding the box 3 m. Now there's and unknown tension on the pulley system. In other words: F f = F N Where is a constant called the coefficient of kinetic friction. The equation becomes a differential equation instead of a singular value. Combining equations 1, 2, and 3 and solving for μ, we have an equation for the angle θ where the force of friction is balanced with the weight component to give zero acceleration, which occurs at. Kinetic friction opposes the motion of the object and is proportional to the normal force acting on an object. The rope is massless and the pulley is frictionless. Attach the Force Sensor to the same cart with the hook toward outside (so you can hold the hook) 2. The vertical acceleration of an object is independent of both its horizontal and its vertical velocity. (Look up 'Inertia Transfer Formula', or 'Parallel Axis Theorum') An alternative would be to draw the drum in a 3d cad program (solidworks, inventor, etc) and then tweak the material density until the inertia matches the catalog value. Adding a mass to the end of a rope does not cause the same acceleration as an equal applied force due to the inertia of the mass itself. frictionless. This can be done by naked eye estimation or. The coefficient of friction between the table and the 10 kg block is 0. The system is then released from rest. The woman exerts a force of 70 N. Two blocks, m 1 = 6. If the object is changing velocity at a constant rate, the object is moving with constant acceleration. com always has the largest selection of New or Used Suzuki Motorcycles for sale anywhere. If we ignore friction the more pulleys in a pulley system the less effort you have to use to lift up a certain load. The rod is acting as a lever for us: if we double the distance or double the force, we get double the torque. How Will You Calculate The Linear Acceleration For Each Trial? Aradius Of The Smart Pulley B. Repeat the procedure with an increased net force. (example: ½ kg x 9. N = Fg Inclined Plane For friction on an inclined plane, the perpendicular and normal forces acting on a sliding object need to be calculated from the angle of the plane (θ). Which of the following is a way of maximizing the system's acceleration? You would then be given options like "maximize M and m and minimize ," or "maximize and m and minimize M. 7 times your own weight. Friction and Motion on Inclined Planes Written by tutor Alex F. Procedure The way to test this theory is to apply a force to an object and measure its acceleration. 0 kg block and a 3. This allows the mass of the system to remain constant, as shown in Figure 5(a). Data collection Click on the icon to open Logger Pro Click collect and release the system. If the frictional torque is 1. Hook the length of string on the force sensor hook, run it through the hole of the cart stopper, then over the pulley, and attach to the 5 g mass hanger over the end. 4x - 8 = 23 Now add 8 to both sides. Two blocks are connected by a rope, through a pulley as shown in this figure. Does a tire or pulley have more friction?. Consider the following two cases (Figures). So if we just solve this now and calculate, we get 4. Redco™ Nylon Cable Sheaves & Pulleys offer high load bearing capabilities (up to 4000 PSI), are light weight, self lubricating and have a low co-efficient of friction. The falling mass spins the disk so that the mass and disk to accelerate together. When this system is released from rest, the pulley turns through 1. To determine the influence of friction between the ramp and the package you run some tests. By carefully choosing the right pulley size and configurations, we can change displacement, speed and acceleration of a pulley-belt system. 385kg m² respectively. It shows that the acceleration is directly proportional to the mass. After initial break-away during accelera - tion the conveyor static friction resistances are zero. Once block B is set into downward motion, it descends at a constant speed. 70kg block on a horizontal, rough surface is attached by a light string that passes over a light, frictionless pulley to a hanging mass of 10. Hint and answer Problem # 3 Two blocks of mass m and M are connected via pulley with a configuration as shown. (Don't forget to.