9.2 The Second Condition for Equilibrium
Net torque must vanish as well as net force, with torque fixed by the force, its lever arm, and the angle between them about a chosen pivot.
College Physics 2e, 9.2 The Second Condition for Equilibrium
4 exercises
9.2 Exercise 1
Which of the following is not an example of an object undergoing a torque?
- A car is rounding a bend at a constant speed.
- A merry-go-round increases from rest to a constant rotational speed.
- A pendulum swings back and forth.
- A bowling ball rolls down a bowling alley.
9.2 Exercise 6
(a) When opening a door, you push on it perpendicularly with a force of 55.0 N at a distance of 0.850m from the hinges. What torque are you exerting relative to the hinges? (b) Does it matter if you push at the same height as the hinges?
9.2 Exercise 8
Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the door. One child pushes with a force of 17.5 N at a distance of 0.600 m from the hinges, and the second child pushes at a distance of 0.450 m. What force must the second child exert to keep the door from moving? Assume friction is negligible.
9.2 Exercise 10
Repeat the seesaw problem in the example with the center of mass of the seesaw 0.160 m to the left of the pivot (on the side of the lighter child) and assuming a mass of 12.0 kg for the seesaw. The other data given in the example remain unchanged. Explicitly show how you follow the steps in the Problem-Solving Strategy for static equilibrium.
Adapted from College Physics © 2022 Rice University. Licensed under CC BY 4.0. Sources: College Physics 2e, College Physics for AP® Courses 2e. Imported at revision f98d7a7.