Physics Practice Tests – Moment of a Force (Questions with Answers and Explanations)

Weights of 0.2 N and 0.5 N are placed at the 30 cm and 80 cm marks respectively on a uniform metre rule. If the meter rule balances horizontally on a knife edge at the 60 cm mark, the weight of the metre rule is ____

A. 0.1 N
B. 0.3 N
C. 0.4 N
D. 0.7 N

A uniform metre rod of mass 1.5 kg is pivoted at one end. A weight of 7 N is placed at the center of the rod. The vertical force which should be applied at the other end to maintain the rod in equilibrium in the horizontal position is _____

A. 22.0 N
B. 11.0 N
C. 10.5 N
D. 2.5 N

In the diagram shown, the moment of the 5 N force about the point X is _____

Calculate the reaction at pivot P.

A light uniform metre rule PT pivoted at Q, the 30 cm mark has a block of mass 1.5 kg suspended at the 80 cm mark as shown in the diagram above. The metre rule is maintained in equilibrium by a string attached at the point R, the 50 cm mark. The tension T in the string is _____