Levers

Question 1

What is a lever?

Answer 1

A lever is a simple machine that consists of a rigid beam that rotates around a fixed point (axis)

Question 2

What are the parts of a lever?

Answer 2

• Force
• Axis
• Resistance

Question 3

What do levers do for us?

Answer 3

A lever will amplify an input force, the output force will allow us to either move a larger mass with less effor, or move an object with greater velocity.

Question 4

What is a first class lever?

Answer 4

Is a lever where the axis is located between the force and resistance.

FAR (force - axis - resistance)

Mechanical advantage = 1 (can be force or speed amplifier depending on location)

Question 5

What is a second class lever?

Answer 5

Is a lever where the resistance arm is less than the force arm, that is, the resistance is acting closer to the axis than the force.

ARF (axis - resistance - force)

Mechanical advantage > 1 (force amplifier)

Question 6

What is a third class lever?

Answer 6

A lever where the resistance arm is greater than the force arm, that is, the resistance is acting further from the axis than the force.

AFR (axis - force - resistance)

Mechanical advantage < 1 (speed amplifier)

Question 7

What is mechanical advantage?

Answer 7

Mechanical Advantage = Force Arm / Resistance

> 1 = lever built to increase force (ARF)
1 = lever is balanced between force and speed (FAR)
< 1 = lever is built to increase speed (AFR)