Question

A uniform metre rule of mass 200g is pivoted at 0cm mark. Calculate the force which would be applied vertically up at the 60cm mark to keep the rule horizontal​

Answer 1

The force needed is 1.7N

Answer 2

Step-by-step explanation:

There are two forces acting on the ruler: weight pulling down halfway at the 50cm mark, and the upward force at the 60cm mark.

Sum of the moments about the pivot:

∑τ = Iα

F (0.60) − (0.200) (9.8) (0.50) = 0

F = 1.63 N