Curve between net forcevs time is shown Initially particle is at rest .. Which of the following best represents the resulting velocity-time graph of the particle ?

A body of mass $m$ moving with velocity $v$ collides head on with another body of mass  $2\, m$ which is initially at rest. The ratio of $K.E.$ of the colliding body before and  after collision will be 

A force of $\left( {2\hat i + 3\hat j + 4\hat k} \right)\,N$ acts on a body for $4\, sec$ and produces a displacement of $\left( {3\hat i + 4\hat j + 5\hat k} \right)\,m.$ The power used is ............. $\mathrm{W}$

The work done by a force $\vec F\, = \,( - \,6{x^3}\,\hat i)N$ , in displacing a particle from $x = 4\,m$ to $x = -\,2\,m$ is .............. $\mathrm{J}$

A light and a heavy body have equal kinetic energy. Which one has a greater momentum

Force acting on a particle moving in a straight line varies with the velocity of the particle as $F = \frac{K}{\upsilon }$  where $K$ is a constant. The work done by this force in time $t$ is