The diagram below represents an ideal pulley system (no mass or friction).What is the force required to lift the 45 kg mass?
A) 442 N
B) 393 N
C) 221 N
D) 147 N

Question

The diagram below represents an ideal pulley system (no mass or friction).What is the force required to lift the 45 kg mass? 
A) 442 N 
B) 393 N 
C) 221 N 
D) 147 N

Quizplus · Accepted Answer

In an ideal pulley system, the force required to lift the mass is equal to its weight divided by the number of supporting ropes. In this case, there are two supporting ropes, so the force required is 45 kg / 2 = 22.5 kg. Since we need to convert this to Newtons, we multiply by the acceleration due to gravity (9.8 m/s^2) to get the answer of 221 N.

The Diagram Below Represents an Ideal Pulley System (No Mass