You are building a catapult to launch a cotton ball. Where should you place the fulcrum to make the cotton ball fly the farthest?
AIn the exact middle of the lever arm
BClose to the cotton ball (load) end
CClose to the end you push down on (effort end)
DIt does not matter where the fulcrum goes
Placing the fulcrum close to the load end gives the effort arm a long distance to push. This means the load end moves through a bigger arc and launches the cotton ball farther. The trade-off is that you need to push harder — but for a cotton ball, that is not a problem because it is very light.
Question 2 True / False
A pair of scissors is an example of two levers working together.
TTrue
FFalse
Answer: True
Scissors are two first-class levers joined at a common fulcrum (the screw or pin in the middle). When you squeeze the handles (effort), the blades (load arms) cut. The closer to the fulcrum you place the paper, the more cutting force the blades apply — that is lever mechanics in action.
Question 3 Short Answer
Explain the trade-off an engineer makes when deciding where to place the fulcrum on a lever.
Think about your answer, then reveal below.
Model answer: Placing the fulcrum closer to the load makes it easier to lift (less force needed) but the load moves less distance. Placing the fulcrum closer to the effort means the load moves farther but requires more force. Engineers choose the fulcrum position based on whether they need more force or more movement.
This force-distance trade-off is the fundamental engineering decision with levers. A crowbar has the fulcrum near the load because prying nails requires lots of force over a small distance. A baseball bat has the fulcrum at the handle end because hitting requires the bat tip to move a large distance quickly.