1. TORQUE
Continued…

2. A person exerts a force 55 N on the end of a door 74 cm wide
A person exerts a force 55 N on the end of a door 74 cm wide. What is the magnitude of the torque if the force exerted is PERPENDICULAR to the door?
41 N m
40.4 N m
40.7 N m
29 N m
28.8 Nm

3. A person exerts a force 55 N on the end of a door 74 cm wide
A person exerts a force 55 N on the end of a door 74 cm wide. What is the magnitude of the torque if the force exerted is at a 45 degree angle to the door?
41 N m
40.4 N m
40.7 N m
29 N m
28.8 Nm

4. Calculate the net torque about the axle of the wheel shown in Fig 8-39
Calculate the net torque about the axle of the wheel shown in Fig Assume a friction torque of 0.40 N m opposes the motion.
25 N m
1.4 N m
15 N m
1.8 N m

5. Concept Questions
INTERTIA + TORQUE = BEST FRIENDS

6. Using a screwdriver, you try to remove a screw from a piece of furniture, but can’t get it to turn. To increase the chances of success, you should use a screwdriver that:
is longer.
is shorter.
has a narrower handle.
has a wider handle.

7. A constant net torque is applied to an object
A constant net torque is applied to an object. Which one of the following will not be constant?
angular acceleration
angular velocity
moment of inertia
center of gravity

8. The two rigid objects shown in this figure have the same mass, radius, and angular speed. If the same braking torque is applied to each, which takes longer to stop? A B
more information is needed

9. A 120 g yo-yo is unwinding its way down a vertical string of length 1
A 120 g yo-yo is unwinding its way down a vertical string of length 1.1 m. Its angular acceleration as it spins downward is 0.78 rad/s^2. The radius of the inner spool about which the string is wound is 3.1 cm. What is the tension in the string?
1.17 N
1.18 N
3.0 N
.094 N

10. A 120 g yo-yo is unwinding its way down a vertical string of length 1
A 120 g yo-yo is unwinding its way down a vertical string of length 1.1 m. Its angular acceleration as it spins downward is 0.78 rad/s^2. The radius of the inner spool about which the string is wound is 3.1 cm. What is the yo-yo’s moment of inertia?
0.047 kg m^2
0.048 kg m^2
1.5 kg m^2
1.6 kg m^2