Newtons Laws

Sand is being dropped on a conveyor belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of v m/s will be:
1. Mv Newton

2. 2Mv Newton

3. $\frac{\mathrm{Mv}}{2}$ Newton

4. zero

An explosion blows a rock into three parts. Two parts go off at right angles to each other. These two are, the first part 1 kg moving with a velocity of 12 ${\mathrm{ms}}^{-1}$ and the second part 2 kg moving with a velocity of 8 ${\mathrm{ms}}^{-1}$. If the third part flies off with a velocity of 4 ${\mathrm{ms}}^{-1}$, its mass would be:

1. 5 kg
2. 7 kg
3. 17 kg
4. 3 kg

A body, under the action of a force , acquires an acceleration of 1 ms^-2. The mass of this body must be:

1. 2 √10 kg

2. 10 kg

3. 20 kg

4. 10 √2 kg

A body of mass hits normally a rigid wall with velocity and bounces back with the same velocity. The impulse experienced by the body is:
1.
2.
3. zero
4.

A rigid ball of mass strikes a rigid wall at and gets reflected without loss of speed, as shown in the figure. The value of the impulse imparted by the wall on the ball will be:

1.		2.
3.		4.

A particle moving with velocity is acted by three forces shown by the vector triangle The velocity of the particle will:

1.	change according to the smallest force
2.	increase
3.	decrease
4.	remain constant

A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is:

1.	along south-west	2.	along eastward
3.	along northward	4.	along north-east