$A$ body of mass $m$ is dropped from a height of $h$. Simultaneously,another body of mass $2m$ is thrown vertically upward with such a velocity $v$ that they collide at a height $h/2$. If the collision is perfectly inelastic,the velocity at the time of collision with the ground will be:

$A$ light inextensible string that goes over a smooth fixed pulley as shown in the figure connects two blocks of masses $m_1 = 0.36 \text{ kg}$ and $m_2 = 0.72 \text{ kg}$. Taking $g = 10 \text{ m/s}^2$,find the work done (in joules) by the string on the block of mass $0.36 \text{ kg}$ during the first second after the system is released from rest.

Consider two carts,of masses $m$ and $2m$,at rest on an air track. If you push both the carts for $3\,s$ exerting equal force on each,the kinetic energy of the light cart is

Starting from rest on her swing at initial height $h_0$ above the ground,Saina swings forward. At the lowest point of her motion,she grabs her bag that lies on the ground. Saina continues swinging forward to reach maximum height $h_1$. She then swings backward and when reaching the lowest point of motion again,she simply lets go of the bag,which falls freely. Saina's backward swing then reaches maximum height $h_2$. Neglecting air resistance,how are the three heights related?

$A$ block of mass '$m$' moving on a frictionless horizontal surface collides with a spring of spring constant '$K$' and compresses it through a distance '$x$'. The maximum momentum of the block after collision is

$A$ train of mass $3 \times 10^6 \ kg$ is accelerated by an engine such that its velocity increases from $5 \ m/s$ to $25 \ m/s$ in $5 \ minutes$. The power of the engine is ........ $MW$.