A large pulley turns at 60 rpm. A smaller pulley 6 in. in diameter turns at 400 rpm. What is the diameter of the larger pulley?
A) 21.5 in.
B) 100 in.
C) 43 in.
D) 50 in.
E) 40 in.

Question

Quizplus · Accepted Answer

The relationship between the diameters and rotational speeds of two pulleys in a belt drive system can be described by the formula $D_1 \times RPM_1 = D_2 \times RPM_2$, where $D_1$ and $D_2$ are the diameters of the pulleys, and $RPM_1$ and $RPM_2$ are their rotational speeds in revolutions per minute. Given that one pulley is 6 inches in diameter and turns at 400 rpm, and the other turns at 60 rpm, we can solve for the diameter of the larger pulley: $6 \times 400 = D_2 \times 60$. Solving for $D_2$ gives $D_2 = \frac{6 \times 400}{60} = 40$ inches.

A Large Pulley Turns at 60 Rpm