Use the parallelogram rule to find the magnitude of the resultant force for the two forces shown in the figure. Round to
one decimal place.
-What is the minimum force required to prevent a ball weighing $20.7 \mathrm { lb }$ from rolling down a ramp inclined $12.2 ^ { \circ }$ with the horizontal?
A) $4.4 \mathrm { lb }$
B) $10.1 \mathrm { lb }$
C) $2.2 \mathrm { lb }$
D) $20.2 \mathrm { lb }$

Question

Quizplus · Accepted Answer

The minimum force required to prevent the ball from rolling down the ramp can be found using the formula for the component of the weight parallel to the incline, which is $w \sin(\theta)$, where $w$ is the weight of the ball and $\theta$ is the angle of the incline. Plugging in the given values, $20.7 \sin(12.2^\circ)$, gives approximately $4.4 \, \mathrm{lb}$, which is the force needed to counteract the component of the gravitational force pulling the ball down the ramp.

Use the Parallelogram Rule to Find the Magnitude of the Resultant