Unit 4: Topic 1 Quiz

Form a hypothesis about how the position of the fulcrum and the location of the load affect the amount of effort force you must exert to lift the load.

• If the distance between the load and fulcrum increases then the effort force always increases.

• The position of the fulcrum has no effect on the effort force needed.
• If the fulcrum is far from the load, then less effort force is required.

• If the fulcrum is close to the load, then less effort force is required to lift it.

Determine the class of the lever in each picture

• C: Second-class lever, B: Third-class lever

  A: First-class lever,

• B: Second-class lever,

  A: First-class lever,

  C: Third-class lever

• B: First-class lever,

  C: Second-class lever,

  A: Third-class lever

You did 1.2 J of work on the lever. If the lever exerted a force of 6.0 N on the brick and moved it a distance of 0.20 m, how much work did the lever do on the brick?

• 1.2 J
• 2.0 J
• 1.5 J
• 1.0 J

Your full backpack weighs 40 N. If you walk down the hall a distance of 16 m, how much work did you do on your books?

• 0 J

• 640 J

• 480 J
• 320 J

If you apply an effort force of 500 N to the branch, and the back of the truck weighs 2500 N, then the mechanical advantage of the branch-lever is

• 5
• 4
• 6
• 10

If the effort arm of the branch-lever were 3 m, and the load arm were 0.3 m, then the mechanical advantage would

• 5
• 0.1

• 20
• 10

you are riding your bicycle. You exert an effort force of 736 N downward as you push on the pedal. The resulting load force that causes the bicycle to move forward is 81 N. Calculate the Mechanical Advantage of the bike pedal lever?

• 0.11

• 10.0
• 1.2
• 0.5

Thinking Critically: Think of a practical use for a lever with a mechanical advantage of 1.

Write a statement explaining how the force needed to pull the car up the ramp relates to the length of the ramp.

• The force needed to pull the car up the ramp is unrelated to the ramp length.
• The force remains constant regardless of the ramp length.
• The force needed increases as the ramp length increases.
• The force needed to pull the car up the ramp decreases as the length of the ramp increases.

What is the lever?

• A lever is a complex machine that requires electricity.
• A lever is a type of pulley used for lifting.
• A lever is a tool used only in construction.
• A lever is a simple machine that amplifies force to lift or move loads. It consists of a bar that rotates around a fixed point called the fulcrum