Question

A pulley system lifts a 500-lb. block 2.0 feet with an effort of only 50 lb. If the 50 lb. moves 30 feet, calculate the efficiency of the pulley system.

Answer 1

Answer:

Efficiency of the pulley system is 66.7 %

Explanation:

It is given that,

Input force, $F_{in}=500\ lb$

Distance, d₁ = 2 feet

Output force, $F_{out}=50\ lb$    

Distance, d₂ = 30 feet

The efficiency of pulley system is defined as ratio of output work done to the input work done i.e.

$\eta=\dfrac{W_{out}}{W_{in}}$

$\eta=\dfrac{500\times 2}{50\times 30}\times 100$

$\eta=66.7\%$      

Hence, the efficiency of the pulley system is 66.7 %    

Answer 2

The answer to this is 67%