Question

Rosa has designed a pulley system for a school science project. She has determined that

as the coefficient of friction increases, the efficiency of the pulley decreases. With a

coefficient of friction of 0.2, the efficiency of the pulley is 75%. What would you expect the

efficiency to be if the coefficient of friction increased to 0.3?

Answer 1

Efficiency decreased to 50%

Explanation:

Given:

Efficiency, E= 75%

Coefficient of friction = 0.2

Let's use the formula :

`E = (k)/(f)`

Substituting figures, we have :

`0.75 = (k)/(0.2)`

`k = 0.75 * 0.2 = 0.15`

To find the efficiency if the coefficient of friction, f, is increased to 0.3, we have:

`E = (0.15)/(f)`

`E = (0.15)/(0.3)`

E = 0.5 ≈ 50%

If the coefficient of friction is increased to 0.3, the efficiency decreased to 50%