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.
Here in this question as we can see there is no air friction so we can use the principle of energy conservation


now here we know that



now plug in all values in above equation

divide whole equation by mass "m"



so height of the ball from ground will be 1.35 m
Answer:
Forces, Gravity, Friction, Direction, Acceleration.