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)
Well, percent (%) means per hundred, and your number is 6. Therefore, you have 6 per hundred, or 6/100. Also, when you have a percent and want to convert it into a fraction, you must divide the percent by 100, so you could just put the six over 100 since the line between the numerator and denominator basically means division.
