A huge box having a mass of 6.80 kg is pulled down along a frictionless surface inclined at 42.00 below the horizontal by a constant force of 7.21 N that is parallel to the incline. The baggage was initially at rest at the top of the ramp and is moving at 5.52 mfs when it reaches the bottom of the ramp. The coefcient of kinetic friction between the box and the inclined surface is 0.39. {a} How much work is done on the box by all forces acting on it? (b) How long is the inclined surface? A 2.70 kg block starts from rest and slides a distance d down a frictionless 32.].O inclined surface. While sliding, it comes into contact with an uncompressed spring of negligible mass and force constant of 760 Nlm. If the height through which the block slides down the inclined is 2.40 m, {a} nd the maximum compression of the spring.(b] What is the speed of the mass when it comes into contact with the spring? (c) What is the initial separation distance d between the mass and the spring? Two blocks of masses m... = 2.90 kg and mB = 6.30 kg are connected by a light string that passes over a frictionless pulley. The block ma resting on a frictionless horizontal tabletop is attached and forced against a horizontal spring of negligible mass with one end fastened on the wall and with force constant of 370 me. When the spring is compressed to 15 cm, the system is suddenly released. Using the principle of energy conservation, (a) what is the speed of the block m,IL when the spring reaches equilibrium? (b) As block m3 continues to descend, the spring is also stretched to the right by mA. What is the maximum distance the spring will be stretched? In a water slide whose total length is 5.5 m as shown in the gure, a 30 kg child slides from the top to the end of the slide and splashes into the water J pool. The child encounters a constant friction between his body and slide of 45. 0 N. {a} What is the speed of the child as he left the water slide? (b) in" What is the speed of the child as it splashes on the pool? I An elevator car has a mass of 800 kg and is carrying passengers having a combined mass of 500 kg. As the elevator ascends, it encounters a constant frictional force of 3600 N. (a) What must be the minimum power delivered by the motor to lift the elevator car at a constant speed of 3.00 mfs? (b) What power must the motor deliver at the instant its speed is 3.00 mfs if it is designed to provide an upward acceleration of 1.00 mfs2? 6. A tennis ball of 0.050 kg was initially pushed down with a velocity of 1.50 mfs from a height of 1.00 m toward the floor. The ball rebounds to a height 35 cm higher than where it was initially. {a} What is the impulse delivered to the tennis ball? [b] If the impact between the floor and the ball lasts for 0.090 5, how much force does the floor exerts on the ball during the collision? 7. A bat strikes a 0.160 kg baseball. Just before impact, the ball is travelling horizontally to the right at 45.0 mfs, and it leaves the bat traveling to the left at an angle of 36.90 above the horizontal with a speed of 60.0 mfs. If the ball and the bat are in contact for 1.75 ms, {a} nd the components of the impulse of the net force on the ball. (b) What is the magnitude and direction of the average force on the ball? In a billiard game, a cue ball of mass 180 g moving to the left at 4.75 mfs collides headon with a stationary target ball of 165 g. If the collision between the balls is elastic, {a} show that the coefcient of restitution is
