Physics 221 Worksheet: Chapter 9, Statics

1) If the resultant force on a body is zero but the torque is not, the body is in

a) translational equilibrium but not rotational equilibrium.

b) rotational equilibrium but not translational equilibrium.

c) translational equilibrium and rotational equilibrium.

d) no kind of equilibrium.

2) A flywheel is in rotational equilibrium. The torque is zero about

a) an axis at the center of the wheel.

b) an axis at the rim of the wheel.

c) both of the above.

d) none of the above.

3) When solving a statics problem, the first thing you must do is

a) draw a free body diagram.

4) The chainwheel (front sprocket) on a bicycle contain 52 teeth. The sprocket on the rear wheel contains 12 teeth. For each revolution of the pedals, the rear wheel will make

a) 1 revolution

b) 52 revolutions.

c) 12 revolutions.

d) 52/12 revolutions.

e) 12/52 revolutions.

5) If the cyclist in problem 4) shifts to a gear with 14 teeth on the rear sprocket but continues to pedal at the same rate

a) the bike will speed up.

b) the bike will slow down.

c) the speed of the bike will not change.

6) The ratio of stress to strain is called

a) elastic force.

b) mechanical advantage.

c) tensile strength.

d) elastic modulus.

7) The maximum stress that a wire can sustain is called

a) elastic force.

b) mechanical advantage.

c) tensile strength.

d) elastic modulus.

8) A certain wire requires a tension of 1000 N to stretch it 1 mm. What tension is required to give a 1 mm stretch to a wire of the same material and length but twice the diameter?

a) 2000 N

b) 4000 N

c) 500 N

d) 250 N

Ans: 1-a, 2-c, 3-a, 4-d, 5-a, 6-d, 7-c, 8-b