Center of Mass - Physics PYQ (Mechanics)

A metal ball of mass 2 kg moving with a velocity of 36 km/h has a head on collision with a stationary ball of mass 3 kg. After the collision, if both balls move together, then the loss in kinetic energy due to collision is

The sum of moments of all the particles in a system about its centre of mass is always

A particle of mass m, moving with a velocity v makes an elastic collision in one dimension with a stationary particle of mass m. During the collision, they remain in contact with each other for an extremely small time T. Their force of contact, with time is shown in the figure. Then, F₀

A ball of mass 3 kg, moving with a speed of 100 ms\(^{-1}\), strikes a wall at an angle 60\(^\circ\) (as shown in figure). The ball rebounds at the same speed and remains in contact with the wall for 0.2 s, the force exerted by the ball on the wall is

Two balls \(A\) and \(B\), of masses \(M\) and \(2 M\) respectively collide each other. If the ball \(A\) moves with a speed of \(150 \mathrm{~ms}^{-1}\) and collides with ball \(B\), moving with speed \(v\) in the opposite direction. After collision if ball \(A\) comes to rest and the coefficient of restitution is 1 (one), then the speed of the ball \(B\) before it collides with ball \(A\) is

As shown in the figure, an iron block \(A\) of volume \(0.25 \mathrm{~m}^3\) is attached to a spring \(S\) of unstretched length 1.0 m and hanging to the ceiling of a roof. The spring gets stretched by 0.2 m . This block is removed and another block \(B\) of iron of volume \(0.75 \mathrm{~m}^3\) is now attached to the same spring and kept on a frictionless incline plane of \(30^{\circ}\) inclination. The distance of the block from the top along the incline at equilibrium is

A ball of mass 0.5 kg moving horizontally at \(10 \mathrm{~ms}^{-1}\) strikes a vertical wall and rebounds with speed \(v\). The magnitude of the change in linear momentum is found to be \(8.0 \mathrm{~kg}-\mathrm{~ms}^{-1}\). The magnitude of \(v\) is

Masses \(m\left(\frac{1}{3}\right)^N \frac{1}{N}\) are placed at \(x=N\), when \(N=2,3,4 \ldots \infty\). If the total mass of the system is \(M\), then the centre of mass is

Ball \(A\) of mass 1 kg moving along a straight line with a velocity of \(4 \mathrm{~ms}^{-1}\) hits another ball \(B\) of mass 3 kg which is at rest. After collision, they stick together and move with the same velocity along the same straight line. If the time of impact of the collision is 0.1 s then the force exerted on \(B\) is

A body of mass 30 kg moving with a velocity $20 \mathrm{~ms}^{-1}$ undergoes one-dimensional elastic collision with another ball of same mass moving in the opposite direction with a velocity of $30 \mathrm{~ms}^{-1}$. After collision the velocity of first and second bodies respectively are

Two blocks of equal masses are tied with a light string passing over a massless pulley (assuming frictionless surfaces ) acceleration of centre of mass of the two blocks is $\left(g=10 \mathrm{~ms}^{-2}\right)$

A steel sphere of radius 1.2 cm collides a second steel sphere at rest. If the collision is elastic and after the collision the first sphere continues to move in its initial direction with a velocity of $\frac{7}{9}$ times its initial velocity, then the radius of the second sphere is

If two bodies of masses 2 kg and 3 kg are moving at right angles with velocities $20 \mathrm{~ms}^{-1}$ and $10 \mathrm{~ms}^{-1}$ respectively, then the velocity of the centre of mass of the system of the two bodies is