Question

A particular lever can lift a load with 80 percent efficiency. If 40 N of effort is applied 2.5 meters from the fulcrum, then what is the maximum load that can be lifted 1.5 m from the fulcrum?

A) 5333 N
B) 1920 N
C) 66.7 N
D) 53.3 N

Answer 1

Refer to the diagram shown below.

For dynamic balance,
1.5W - 2.5F = 0
W = (2.5*F)/1.5
= (2.5*40)/1.5
= 66.667 N

Because the lever is 80% efficient, the actual maximum load that can be lifted is
0.8*66.667 = 53.3 N

Answer: D. 53.3 N