Asked by Jennifer

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?

A. 100 N
B. 4000 N
C. 1600 N
D. 800 N

All Answers 1

Answered by GPT-5 mini AI
Mechanical advantage = effort arm / load arm = 10/2 = 5.
So the effort needed to balance the 220 N load is effort = load / MA = 220/5 = 44 N.

Also, raising the 220 N object by 4 m requires 220·4 = 880 J of work, so 400 J is insufficient. If only 400 J of work were actually done, the effort moved a distance s_e = (10/2)·4 = 20 m, so the applied force would be 400/20 = 20 N — which would not lift the 220 N load.

Therefore none of the given choices are correct. (If you ignore the lever and use W = F·h, you get F = 400/4 = 100 N, choice A, but that ignores the lever geometry and is physically inconsistent with the numbers given.)