AS Physics Moments

The diagram shows a uniform door hanging from two hinges 2.5 m apart. The moment of the couple that the hinges exert on the door is.....

• 150 Nm

• 200 Nm

• 250 Nm

• 500 Nm

The rectangular objects, A, B, C and D are each 2 cm long and 1 cm high. Which one of the bodies is in equilibrium?

• 
• 
• 
• 

A uniform square block is sliding with uniform speed along a rough surface as shown in the diagram. The force used to move the block is 200 N. The moment of the frictional force acting on the block about the centre of gravity of the block is:

 

• 150 N m, clockwise

• 150 N m, anticlockwise

• 300 N m, clockwise

• 300 N m, anticlockwise

A car wheel nut can be loosened by applying a force of 200 N on the end of a bar of length 0.8 m as in X. A car mechanic is capable of applying forces of 500 N simultaneously in opposite directions on the ends of a wheel wrench as in Y.

What is the minimum length l of the wrench which would be needed for him to loosen the nut?

• 0.16 m

• 0.32 m

• 0.48 m

• 0.64 m

The diagram shows a uniform metre ruler of weight 1.5 N pivoted 15 cm from one end for use as a simple balance. A scale pan of weight 0.5 N is placed at the end of the ruler and an object of unknown weight is placed in the pan. The ruler moves to a steady horizontal position when a weight of 2.5 N is added at a distance of 60 cm from the pivot as shown.

What is the weight of the object?

• 9.5 N

• 10.0 N

• 13.0 N

• 13.5 N

A light uniform rigid bar is pivoted at its centre. Forces act on the bar at its ends and at the centre.

Which diagram shows the bar in equilibrium?

• 
• 
• 
• 

A uniform rod is balanced horizontally about a support F. Forces of 400 N and 100 N act at the ends of the rod, as shown. What is the reaction force acting on the rod at support F?

• 100 N

• 500N

• 550N

• 600N

 bird sits on a uniform rod suspended from vertical wires P and Q. The rod has a weight W and is 15.0 cm long.

The weight of the bird is 2W and acts at a distance x from P.

What is the value of x when the tension in P is half the tension in Q?

• 7.50 CM

• 10 CM

• 11.3 CM

• 15.0 CM

A uniform beam of weight 23.5 N is attached by a hinge to a vertical wall and supported by a string.

The string makes an angle of 35° to the wall. What is the tension in the string?

• 14 N

• 21 N

• 29 N

• 41 N

The diagram shows the forces acting on a uniform rod. Which statement is correct?

• The rod is in equilibrium

• For equilibrium, an anticlockwise moment of 1.0 N m is needed.

• For equilibrium, a clockwise moment of 1.0 N m is needed.

• For equilibrium, the 10 N force should be increased to 20 N.