A light spring of length $20\, cm$ and force constant $2\, kg/cm$ is placed vertically on a table. A small block of mass $1\, kg$. falls on it. The length $h$ from the surface of the table at which the ball will have the maximum velocity is ............... $\mathrm{cm}$
$20$
$15$
$10$
$5$
In a system of particles, internal forces can change (for the system)
A space craft of mass $'M' $ and moving with velocity $ 'v' $ suddenly breaks in two pieces of same mass $m$. After the explosion one of the mass $ 'm'$ becomes stationary. What is the velocity of the other part of craft
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 simple lets go off 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 ball is projected from top of a tower with a velocity of $5\,\, m/s$ at an angle of $53^o$ to horizontal. Its speed when it is at a height of $0.45 \,\,m$ from the point of projection is ........ $m/s$
A bomb is projected upwards. At topmost point it explodes in three identical fragments. First fragment comes to ground in $10\ sec$. and others in $20\ sec$ each. Then the height reached by the original bomb is.........$m$