Question

A 36-N crate is suspended from the left end of a plank. The plank weighs 21 N, but it is not uniform, so its center of gravity does not lie halfway between the two ends. The system is balanced by a support that is 0.30 m from the left end of the plank. How far to the right of the support is the plank’s center of gravity?

Answer 1

Answer:

0.51 m

Explanation:

from the question we are given the following

weight of the crate = 36 N

weight of the plank = 21 N

distance of of the balance from the left end = 0.3 m

from the diagram attached, CG is the center of gravity ( the point near or within a body through which its weight can be assumed to act ), taking the CG as where the weight of the plank acts and it being at a distance L from the support

we can find the distance of the center of gravity just as we would find the moment about the support balance

therefore

36 x 0.3 = 21 x L

10.8 = 21L

L = 0.51 m

The center of gravity is 0.51 m to the right of the support.