1) Do all points on a rigid, rotating body have the same angular acceleration? Support your answer.

2) Suppose that a heavy person and a light person are balanced on a teeter-totter made of a plank of wood. Each person now moves in toward the fulcrum a distance of 25 cm. What effect will this have on the balance of the teeter-totter?

A) The teeter-totter will remain in balance.

B) The heavy person’s end will go down.

C) The light person’s end will go down.

D) One cannot tell whether either end will rise or fall without knowing the relative mass of the plank.

E) Only if the plank has significant mass will the light person’s end go down.

3) Which of the following is an accurate statement?

A) The ratio stress/strain is called the elastic modulus.

B) “Strain” has a meaning very close to “force.”

C) “Stress” has a meaning very close to “stretch.”

D) Tensile stress is measured in Newtons.

E) Tensile strain is measured in meters.

4) In the figure, a certain type of string will break if the tension in the string exceeds  300 N. A number of 8-kg weights are hung one below the other from a hook in the ceiling using this string. The number of weights that causes the string to break and the string segment that will break are as follows:

A) When the  4th weight is added, the top string segment will break.

B) Each segment has a tension of  78.4000015 N, and there is no limit to the number of weights that can be suspended.

C) When the  4th weight is added, the bottom string segment will break.

D) When the  4th weight is added, all string segments will break.

E) When the  38th weight is added, all string segments will break.

5) The figure shows two forces acting on an object. They have magnitudes F1 = 9.6 N and

F2 = 3.2 N. What third force will cause the object to be in equilibrium?

A) 10 N at 162° counterclockwise from

B) 10 N at 108° counterclockwise from

C) 6.4 N at 162° counterclockwise from

D) 6.4 N at 108° counterclockwise from

6) Two blocks, A and B, are being pulled to the right along a horizontal surface by a horizontal 100 N pull, as shown in the figure. Both of them are moving together at a constant velocity of 2.0 m/s to the right, and both weigh the same. Which of the figures below shows a correct free-body diagram of the horizontal forces acting on lower block, B?

A)

B)

C)

D)

E) None of these diagrams is correct.

7) A man pushes against a rigid, immovable wall.  Which of the following is the most accurate statement concerning this situation?

A) The man can never exert a force on the wall that exceeds his weight.

B) If the man pushes on the wall with a force of 200 N, we can be sure that the wall is pushing back with a force of exactly 200 N on him.

C) Since the wall cannot move, it cannot exert any force on the man.

D) The man cannot be in equilibrium since he is exerting a net force on the wall.

E) The friction force on the man’s feet is directed to the left.