Simple Machines and Mechanical Advantage Questions and Answers Flashcards
7 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Simple Machines and Mechanical Advantage Questions and Answers flashcards as text
A screw has 8 threads per inch. How far does it advance into a material with one complete revolution?
Answer: 0.125 inches
The pitch (advance per revolution) equals 1 divided by threads per inch: 1 ÷ 8 = 0.125 inches.
What is the ideal mechanical advantage of a single movable pulley?
Answer: 2
A single movable pulley has a mechanical advantage of 2 because two rope segments support the load, halving the required effort.
An inclined plane with a mechanical advantage of 5 requires 40 lbs of input force. What load can it raise?
Answer: 200 lbs
Output force = Mechanical advantage × Input force = 5 × 40 = 200 lbs.
Machine efficiency is calculated as:
Answer: Output work ÷ Input work × 100%
Efficiency = (Output work ÷ Input work) × 100%; a perfect machine would be 100% efficient, but friction always reduces this.
A doorknob is an example of which simple machine?
Answer: Wheel and axle
A doorknob is a wheel and axle — the large knob is the wheel and the spindle (latch shaft) is the axle, multiplying torque.
A compound machine combines two or more simple machines. Its primary advantage over a single simple machine is:
Answer: It can achieve a greater mechanical advantage
Combining simple machines multiplies their individual mechanical advantages, allowing very large forces to be overcome with small effort.
You push a 200 lb box up a ramp that is 8 ft long and 2 ft high. Ignoring friction, how much force is needed?
Answer: 50 lbs
IMA = 8 ÷ 2 = 4; required force = 200 ÷ 4 = 50 lbs.