PEP 111 Quiz_3_S2017_solutions| graded

Problem 1: B Problem 2: G Problem 3: G Problem 4 (a): C Problem 4 (b): A Problem 5: B Problem 6: A Problem 7 (2 points) A block of mass m1 = 5.0 kg is connected by a string over a pulley, which is massless and frictionless, to a ball of mass m. The block and the ball are initially held at rest, but then they move together with the block sliding to the right and the ball descending. There is no friction between the surface of the table and the block. When the ball has descended a distance of h = 3.0 m the speed is measured at v = 5.0 m/s. Calculate the ball’s mass m2. ∆K1 + ∆K2 + ∆Ug2 = 0 or ∆K1 + ∆K2 = Wg with Wg = m2gh (1/2)m1v2 − 0 + (1/2)m2v2 − 0 + 0 − m2gh = 0 m2(gh − v2/2) = (1/2)m1v2 m2 = (1/2)m1v2 / (gh − v2/2) = 62.5 [kg⋅m2/s2] / 16.9 [m2/s2] = 3.7 [kg] Problem 8 (4 points) A block of mass m = 3.0 kg is initially at rest on a ramp at position A, which is at a height of h = 2.0 m above the ground, as shown in the figure below. The block then slides down the ramp, which has no friction, and slides to the right on the floor, which between the ramp and the position B also does not have friction. However, to the right of position B the floor does have a coefficient of kinetic friction of µk = 0.40. The block slows down after position B and comes to a stop at position C, which is a distance of L to the right of position B. (a) (2 points) Calculate the distance L in units of meters. 1 b) At what point does the ball have (c) What is this maximum speed? of friction ck of mass the surface mk 5 0.400. from rest. of the ball kg when it ance h 5 is set into lined plane eed of vi 5 P8.23). The st after travm along the inclined at 30.08 to the his motion, change in the block’s kinetic energy, n the potential energy of the block– (c) the friction force exerted on the o be constant). (d) What is the coefriction? s held 1.20 m above a relaxed massg with a force constant of 320 N/m. ped onto the spring. (a) How far does ess the spring? (b) What If? Repeat ime assume a constant air-resistance acts on the object during its motion. ar does the object compress the spring riment is performed on the Moon, s2 and air resistance is neglected? pressed against a spring of force /m until the block compresses the m1 m2 Figure P8.22 d u vi Figure P8.23 h v PThe line from the center of the pumpkin makes an angleWhile you happen to be standof a rainy night, a breath of wstart sliding downward from the cap when the line from sphere to the pumpkin makesvertical. What is this angle? 67. Review. The mass of a car is 1car’s body is such that its aerois D 5 0.330 and its frontal athe drag force is proportionalsources of friction, calculatemaintain a speed of 100 km/hhill sloping at 3.208. 68. A pendulum, comprising a lstring of length L and a smsphere, swings in the vertS 63. A 10.0-kg block is released from rest at point ! in Figure P8.63. The track is frictionless except for the portion between points " and #, which has a length of 6.00 m. The block travels down the track, hits a spring of force constant 2 250 N/m, and compresses the spring 0.300 m from its equilibrium position before coming to rest momentarily. Determine the coefficient of kinetic friction between the block and the rough surface between points " and #. 3.00 m 6.00 m ! " # Figure P8.63 64. A block of mass m1 5 20.0 kg is M L PrThe line from the center of cthe pumpkin makes an angle uWhile you happen to be standinof a rainy night, a breath of wistart sliding downward from rethe cap when the line from tsphere to the pumpkin makes vertical. What is this angle? 67. Review. The mass of a car is 1 5car’s body is such that its aerodis D 5 0.330 and its frontal arethe drag force is proportional tsources of friction, calculate maintain a speed of 100 km/h hill sloping at 3.208. 68. A pendulum, comprising a ligstring of length L and a smsphere, swings in the verticplane. The string hits a peg locatS 63. A 10.0-kg block is released from rest at point ! in Figure P8.63. The track is frictionless except for the portion between points " and #, which has a length of 6.00 m. The block travels down the track, hits a spring of force constant 2 250 N/m, and compresses the spring 0.300 m from its equilibrium position before coming to rest momentarily. Determine the coefficient of kinetic friction between the block and the rough surface between points " and #. 3.00 m 6.00 m ! " # Figure P8.63 64. A block of mass m1 5 20.0 kg is connected to a block of mass M AMT h This study source was downloaded by from CourseH on 11-16-202