Answer to Question #241074 in Mechanics | Relativity for Haris

Question

Calculate the tension in the rod if the pub sign is an 80, c, m,

80cm square of mass 30, k, g,

30kg. Ignore the mass of the rod, assume that the hinge is well-oiled, and assume that the mass is evenly distributed in the sign. Give your answer to 2 significant figures.

Answer 1

You have to calculate the centre of gravity of the sign, and calculate the vertical component of the metal rod, and taking moments at the hinge.

For a system to be in equilibrium, the net force = 0 and the moments = 0, so it is not accelerating or rotating.

ension = mg

m= mass = 30kg

g= acceleration due to gravity= 9.81

T= 30 x 9.81

T= 294.3

T=290 N