The force 'F' acting on a particle of mass 'm' is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from 0 to 8 s is : 
      

1. 24 Ns

2. 20 Ns

3. 12Ns

4. 6 Ns

A body of mass (4m) is lying in the x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (u). The total kinetic energy generated due to explosion is:

1. $m{u}^2$

2. 1.5$m{u}^2$

3. 2$m{u}^2$

4. 3$m{u}^2$

A body of mass M hits normally a rigid wall with velocity v and bounces back with the same velocity. The impulse experienced by the body is:

1.  1.5Mv

2.  2Mv

3.  zero

4.  Mv

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 $\overrightarrow{\mathrm{F}}=6\hat{i}-8\hat{j}+10\hat{k}$, 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

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