Application Of Laws

A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle of ${\mathrm{30°}}^{\mathrm{}}$ with the wall. It is reflected with the same speed and at the same angle. If the ball is in contact with the wall for 0.25 s, the average force acting on the wall is:

1. 48 N

2. 24 N

3. 12 N

4. 96 N

The mass of a lift is kg. When the tension in the supporting cable is N, then its acceleration is:
(Take m/s²)

1.	ms-2 downwards	2.	ms-2 upwards
3.	ms-2 downwards	4.	ms-2 upwards

Three blocks with masses , , and are connected by strings as shown in the figure. After an upward force is applied on block , the masses move upward at constant speed . What is the net force on the block of mass ? ( is the acceleration due to gravity)

A block of mass is placed on a smooth inclined wedge of inclination as shown in the figure. The wedge is given an acceleration ' ' towards the right. The relation between and for the block to remain stationary on the wedge is:

1.		2.
3.		4.

A horizontal force is applied to a block as shown in figure. The mass of blocks and are and , respectively. The blocks slide over a frictionless surface. The force exerted by block on block is :

1.
2.
3.
4. zero