Mechanical advantage — Science definition
Output force divided by input force.
Where it is taught
- Mechanical Advantage — Work & Machines, Physical Science: Matter, Forces & Energy, Grade 8
In use
Mechanical advantage tells how a machine changes force: actual mechanical advantage = output force ÷ input force.
Mechanical Advantage
Questions using mechanical advantage
Problem 1
A machine provides 45 N output for 15 N input. Find actual mechanical advantage.
Answer and explanation
3
45 ÷ 15 = 3.
Problem 2
An ideal ramp is 3 m long and 1 m high. Find ideal mechanical advantage.
Answer and explanation
3
Length ÷ height = 3 ÷ 1.
Problem 3
A machine lifts a 120 N load with 40 N effort. Find actual mechanical advantage. Explain the reasoning in your own words.
Answer and explanation
Mechanical advantage is 3; this does not specify efficiency without distances.
Mechanical advantage=output force/input force.
120/40=3; the force units cancel.
Response criteria
- Use the stated conditions.
- Show the evidence or calculation.
- Explain the conclusion and any stated limitation.
Problem 4
A device delivers 96 N using 24 N input. Calculate actual mechanical advantage. Show the reasoning, not just the conclusion.
Hints
It describes force multiplication, not energy creation.
Answer and explanation
96/24=4.