Question

Question
A lever with an effort arm of 10 meters and a load arm of 2 meters is used to lift an object weighing 220 Newtons to a height of 4 meters. If 400Joules of work is done, how much force must have been applied?(1 point)
Responses

800 N
800 N

1600 N
1600 N

4000 N
4000 N

100 N
100 N

Answer 1

First find the required work to lift the load: W = weight · height = 220 N · 4 m = 880 J.
With a lever (effort arm 10 m, load arm 2 m) the mechanical advantage = 10/2 = 5, so the ideal effort force is
F = 220 N / 5 = 44 N.

Note: if the effort moves, it travels s_e = (10/2)·4 m = 20 m, so input work = 44 N · 20 m = 880 J. Therefore the statement “400 J of work is done” is inconsistent (400 J is less than the 880 J required), so none of the multiple‑choice answers is the correct ideal value.

(If you instead ignore the lever and simply use W = F·d with W = 400 J and d = 4 m you get F = 100 N — which matches one listed choice — but that neglects the lever and is physically inconsistent with the lifting task.)