A screw jack has a handle 40 centimetres long and a thread pitch of 0.5 centimetres per turn. What is its approximate ideal mechanical advantage?

Correct answer to question 168 (Mechanical Comprehension): about 503

Method

Ideal mechanical advantage of a screw jack is roughly the circumference of the handle's circle divided by the pitch: (2 x pi x 40) / 0.5 is approximately 502.