A lever is used to lift a heavy load. When a 30-N force pushes one end of the lever down 1.4 m, the load rises 0.2 m. What is the weight of the load?

Answer: 260N

Explanation:

This question will be solved based on the assumption that efficiency is 100% ie 1

Efficiency = work done by the machine (work output) / work done on the machine (work input)

Since Workdone = Force * Distance

Work output = Load * distance moved by load = 0.2*Load

Work input = Effort*distance moved by effort = 30*1.4 = 52 Joules

Substituting this value info the efficiency formula we have

1 = 0.2Load/52

52 = 0.2 * Load

Load = 52/0.2

Load = 260N

Therefore, the weight of the load is 260N