Question

A screwdriver moves 16cm with 20 N of applied force to pry the lid from a paint can. What efficiency is obtained if the screwdriver produces 288 N and moves the lid 1 cm?

Answer 1

Number of centimeters that the screwdriver should move with 288 N is:

 288 (16/20) = 230.4

 So, we have: If 230.4 is your 100%, then what percentage is 1 centimeter

 (1/230) = 0.00434

 If you multiply it by 100, you get:

 0.00434x100 = 0.43%

 What efficiency is obtained if the screwdriver produces 288 N and moves the lid 1 cm?

 The efficiency is 0.43%