Question

What is the minimum force required to prevent a ball weighing 22.6 lb from rolling down a ramp which is inclined at 39.0 degrees with the horizontal?
A. 7.1 lb

B. 8.8 lb

C. 17.6 lb

D. 14.2 lb

Answer 1

The correct answer is 14.2 lb which is choice D.

Let:

F = minimum force required to prevent ball from rolling down the ramp

The formula will be:

F = w * sin theta

F = w * sin (39 degrees)

F = 22.6 * sin (39) 
= 14.2 lb (this is rounded to the nearest tenth)