Force and Motion: Law of levers

The video explains the law of levers, which states that the effort force times its arm equals the resistance force times its arm. It explores the three classes of levers: first class, where the fulcrum is between resistance and force; second class, where resistance is between fulcrum and force; and third class, where force is between resistance and fulcrum. The video discusses how each class of levers can either conserve or not conserve effort, using examples like crowbars, nutcrackers, and manual brooms.

What is the fundamental law of levers?

• Effort force is always less than resistance force

• Effort force is always greater than resistance force

• Resistance force times its arm equals effort force squared

• Effort force times its arm equals resistance force times its arm

In the first class of levers, when does it conserve effort?

• When the arm of force is shorter than the arm of resistance

• When the arm of force is equal to the arm of resistance

• When the arm of resistance is twice the arm of force

• When the arm of force is longer than the arm of resistance

What is unique about the second class of levers?

• The force is between the resistance and fulcrum

• The resistance is always greater than the force

• The resistance is between the fulcrum and force

• The fulcrum is between the force and resistance

Which example illustrates the second class of levers?

• Manual broom

• Nutcracker

• SISO

• Crowbar

In the third class of levers, why is more effort required?

• The arm of force is shorter than the arm of resistance

• The arm of force is longer than the arm of resistance

• The resistance is negligible

• The arm of force is equal to the arm of resistance