(2) In 1990, Walter Arfeuille, of Belgium, lifted a 281.5-kg object through a distance of 17.1 cm using only his teeth.
(a) How much work did Arfeuille do on the object?
(b) What magnitude force did he exert on the object during the lift, assuming the force is constant?
(5) Starting from rest, a 5.00 kg block slides 2.50 m down a rough 30.0 degree incline. The coefficient of kinetic friction between the block and the incline is μk = 0.436. Determine:
(a) the work done by the force of gravity,
(b) the work done by the friction force between block and incline, and
(c) the work done by the normal force.
(10) A 7.00-kg bowling ball moves at 3.00 m/s. How fast must a 2.45-g Ping Pong ball move so that the two balls have the same kinetic energy?
(15) A 7.80-g bullet moving at 575 m/s penetrates a tree trunk to a depth of 5.50 cm. (a). Use work and energy considerations to find the average frictional force that stops the bullet. (b). Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.
(23) A 2100 kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 7.00 m before coming into contact with the top of the beam, and it drives the beam 12.0 cm farther into the ground before coming to rest. Using energy considerations, calculate the average force the beam exerts on the pile driver while the pile driver is brought to rest.
(24) Two blocks are connected by a light string that passes over two frictionless pulleys as in figure P5.24. The block of mass m2 is attached to a spring of force constant k and m1 > m2. If the system is released from rest, and the spring is initially not stretched or compressed, find an expression for the maximum displacement d of m2.
(36) A block of mass m = 5.00 kg is released from rest from point A and slides on the frictionlesss track shown in figure P5.36. Determine (a) the block's speed at points B and C and (b) the net work done by the gravitational force on the block as it moves from point A to C.
(59) The force acting on a particle varies as in Figure P5.59.
Find the work done by the force as the particle moves (a) from x = 0 to x = 8.00 m, (b) from x = 8.00 to
x = 10.0 m, ad (c) from x = 0 to x = 10.0 m.
Solution:
(66) A ball of mass m = 1.80 kg is released from rest at a height h = 65.0 cm above a light vertical spring of force constant k. The ball strikes the top of the spring and compresses it a distance d = 9.00 cm. Neglecting any energy losses during the collision and assuming that the ball sticks to the top of the spring (no bounce), calculate the force constant of the spring.
(71) Two objects (m1=5.00kg and m2=3.00kg) are connected by a light string passing over a light, frictionless pulley.
The 5.00kg object is released from rest at a point h = 4.00 m above the table.
(a.) Determine the speed of each object when the two pass each other.
(b.) Determine the speed of each object at the moment the 5.00kg object hits the table.
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