Question

Two pullies are used in a system. Pully A tums 1.5 turns for each 1 turn of pully B AND it pulls in the opposite direction. If + is counterclockwise, and is

clockwise, How many times does pully A tum when pully B tums 80 times counterclockwise?
A) +80
B) -120
C) -60. D) +40​

Answer 1

Answer: B) -120

Explanation:

Set up a proportion, cross multiply, and solve.

`\frac{\text{Pulley A:}}{\text{Pulley B:}}\quad (-1.5\ turns)/(1\ turn)=(x)/(80\ turns)\\\\\\\text{Cross multiply:}\quad -1.5(80)=x\\\\.\qquad \qquad \qquad \qquad \quad \large\boxed{-120=x}\\`