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

1600 N
1600 N

800 N
800 N

4000 N
4000 N

100 N

Answer 1

Mechanical advantage = effort arm / load arm = 10/2 = 5.
If the load rises 4 m, the effort moves 5×4 = 20 m.
So if 400 J of work is done by the effort, the applied force F = W / distance = 400 / 20 = 20 N.

Note: this is inconsistent physically — lifting a 220 N weight 4 m requires 220×4 = 880 J of output work, so 400 J input is insufficient. None of the given choices are correct.