Question

(b) A painter sets up a uniform plank so he can paint a wall.

1
1
1
0.5 m
force A
weight of plank
500 N
force B
0.5 m
length of plank
3 m
The plank is 3 m long and weighs 500 N.
(i) Use the principle of moments to show that the upward force A is 250 N.

Answer 1

The upward force A is determined to be 250N using the principle of moments.

Step-by-step explanation:

To determine the upward force A, we can use the principle of moments. The total anticlockwise moment produced by the weight of the plank is equal to the total clockwise moment produced by force A. Given that the length of the plank is 3 m and its weight is 500 N, we can calculate the force A using the formula:

Total anticlockwise moment = Total clockwise moment

(500 N) * (0.5 m) = A * (3 m)

Solving for A:

A = (500 N) * (0.5 m) / (3 m) = 250 N

Learn more about Principle of Moments