QUESTION 1 A horizontal force, F, acts on a crate weighing 8 N, which moves on a horizontal floor at constant speed. The coefficient of friction between the crate and the surface is 0.25. The work done by F when the crate has moved 12 m is: 0 J 2 J 10 J 24 J 96 J None of the above 2 points

QUESTION 2 You and your friend push against a wall. Your friend stops after 10 minutes, while you push for 5 minutes longer. Compare the work you and your friend do. You do 50% more work than your friend. Your friend does 50% more work than you. You do 75% more work than your friend. Neither you nor your friend do any work. 2 points

QUESTION 3 John pulls a sled on a frictionless surface with a force of 60 N at an angle of 37 above the horizontal. If he pulls it a distance of 12 m, the work he does is: 185 J 433 J 575 J 720 J 2 points

QUESTION 4 A driver, traveling at 22.0 m/s, slows down her car and stops. What work is done by the friction force against the wheels if the mass of the car is 1500 kg? 4.50 x 106 joules 3.67 x 106 joules 4.50 x 105 joules 3.63 x 105 joules None of the above 2 points

QUESTION 5 56 J of work was done to increase the kinetic energy of a 1.90 kg mass. If the object's initial velocity was zero, what is its speed now? 59.0 m/s 56.0 m/s 1.90 m/s 7.68 m/s None of the above 2 points

QUESTION 6 A bullet with a mass of 3.0 gram, moving at speed of 300 m/s, hits and embeds itself in the trunk of a tree. The tree exerts an average force of 250 N on the bullet. What is the distance the bullet travels inside the trunk? 0.27 m 0.54 m 0.81 m 1.1 m 1.3 m None of the above 2 points

QUESTION 7 A 5 kg bowling ball is moving at 6 m/s. In order to change its speed to 10 m/s, the net work done on the bowling ball must be: 40 J 90 J 160 J 400 J 550 J None of the above 2 points

QUESTION 8 A 40.0 N cart slides from rest down a rough 6.0 m long ramp inclined at 30.0 with the horizontal. Find the velocity of the cart at the bottom of the ramp if the force of friction between the crate and ramp is 6.0 N. (Hint: Since the answers are given to two digits of accuracy, use g = 9.8 m/s2.) 8.7 m/s 3.3 m/s 4.5 m/s 6.4 m/s None of the above 2 points

QUESTION 9 A 3 kg object traveling at 4 m/s is pushed by a net force of 5 N. The speed increases to 6 m/s. Find the distance the object travels. 40.0 cm 1.20 m 4.80 m 6.00 m None of the above 2 points

QUESTION 10 A 6000 N crate is pulled across an icy surface. The coefficient of kinetic friction is 0.050. The work done in pulling the crate 1000 m at constant velocity is: 3.1 x 104 J 1.5 x 105 J 3.0 x 105 J 2.9 x 106 J 6.0 x 106 J 2 points

QUESTION 11 The work required to accelerate an object initially at rest to a speed vf is W. What is the additional work needed to increase its speed from vf to 2vf? W W/2 2W 3W none of them 2 points

QUESTION 12 When a spring is stretched a distance x, it exerts a restoring force of magnitude F = Ax, where A is a constant. Find the work required to stretch the spring from x = 0 to x = L: AL2 A + 2L A + 2L2 A/L AL2/2