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 a mass is equal to the weight of the mass divided by the number of segments of rope supporting the mass. Since there are two segments of rope supporting the 45 kg mass in this diagram, the force required to lift it is (45 kg x 9.8 m/s²) / 2 = 221.25 N, which can be rounded to 221 N. Therefore, the correct answer is C.

The Diagram Below Represents an Ideal Pulley System (No Mass