7) A 200 g box is placed on a board at a incline and accelerates from rest down the board at 0.1 m/ . (a) How long does the box take to travel down the board of length 1 m? (b) What is the magnitude of the frictional force that opposes the motion of the box? (c) What is the coefficient of friction between the box and the board?

a)

b)

c)

8) A 4.5 kg block is thrust up a inclined plane with an initial speed of 5.0 m/s. It is found to travel 1.5 m along the plane, stop, and slide back to the bottom. Compute the force of friction (assumed to have a constant magnitude) acting on the block and find the speed v of the block when it returns to the bottom of the inclined plane.

9) A pendulum of mass m = 1 kg and length l = 1 m is released from a horizontal position. At the bottom of its swing, it collides elastically with a mass M = 3 kg. (a) What is the velocity of the mass M right after collision? (b) To what height above its low point does mass m rebound?

a)

(eq.1)

(eq.2)

(eq.1)+(eq.2)

b) (eq.2)

10) One mole of an ideal monoatomic gas at an initial volume L follows the cycle shown in the figure below. All the processes are quasi-static. Find (a) the temperature of each state of the cycle, (b) the heat flow for each part of the cycle, (c) the efficiency of the cycle. For a monoatomic gas, and . a)

b)

c)