IGCSE Physics : Moments – Numerical Practice Questions

1.  A mechanic applies a force of 200N at the end of a spanner of length. What moment is applied to  the nut? 

2. A boy weighing 400N sits 1.5 m from the pivot of a see saw. Where should a girl weighing  300N sit to balance the see saw? 

3.  A meter ruler is pivoted at its mid-point .A 1.0N weight is suspended from the 20cm mark and a 2.0N weight from the 80cm mark. Where must an upward force of 4.0N be applied to balance the ruler? 

4.  A tapered rod of mass 200g is 160cm long. It balances at its mid-point when a 150g mass hang from its narrow end. How far is the centre of gravity from the thick end? 

5.  A uniform plank of length 4.4 m and weighing 200N is placed horizontally on two trestles which are 3.2m apart and at equal distance from the ends of the plank. A man weighing 800N stands on the plank over one of the supports. a) Calculate the force on each support. b) How far could the man move towards the end nearer to him before the plank starts to tip?

6.  BRIEFLY explain each of the following:  

A door handle is placed well away from the hinge.

It is difficult to steer a bicycle by gripping the centre of the handle bars.

Racing cars are low with wheels wide apart

A wine glass is less stable when it contains wine

A desk lamp has a wide heavy base.