Question

A uniform plank of length 3 m is supported by two wooden trestles L and M as shown in the diagram above. L exerts a force of 80n upwards and M a force of 160N upwards. M is O.5m from the centre of gravity of the plank.
calculate the weight w of the plank and by taking moments about the centre of gravity find the value of x

Answer 1

Hhb

Answer 2

upward force= downward force
Weight(W)= 80N+160N
W= 240N

Value of X,
forces in one direction=forces in opp direction
160N multiplied by 0.5= 80N multiplied by X
which gives.....
80N= 80N multiplied by X
X= 80/80
X=1

i hope you get it