Center Of Mass - Mechanics - Physics Previous Year Questions

A block of mass ' $m$ ' moving on a frictionless surface at speed ' $v$ ' collides elastically with a block of same mass, initially at rest. Now the first block moves at an angle ' $\theta$ ' with its initial direction and has speed ' $v_1$ '. The speed of the second block after collision is

A batsman hits a ball of mass 0.2 kg straight towards the bowler without changing its initial speed of \(6 \mathrm{~m} / \mathrm{s}\). What is the impulse imparted to the ball?

A bullet of mass \(m\) moving with velocity \(v\) is fired into a wooden block of mass \(M\), If the bullet remains embedded in the block, the final velocity of the system is

$N$ number of balls of mass $m \mathrm{~kg}$ moving along positive direction of $X$ - axis, strike a wall per second and return elastically. The velocity of each ball is $u \mathrm{~m} / \mathrm{s}$. The force exerted on the wall by the balls in newton, is

In system of two particles of masses $m_1$ and $m_2$, the first particle is moved by a distance $d$ towards the centre of mass. To keep the centre of mass unchanged, the second particle will have to be moved by a distance

Two masses '\(m_{\mathrm{a}}\)' and '\(\mathrm{m}_{\mathrm{b}}\)' moving with velocities '\(v_{\mathrm{a}}\)' and '\(v_{\mathrm{b}}\)' opposite directions collide elastically. Alter the collision '\(m_a\)' and '\(m_b\)' move with velocities and '\(v_{\mathrm{b}}\)' and '\(v_a\)' respectively, then the ratio \(\mathrm{m_a:m_b}\) is

A molecule of mass 'm' moving with velocity 'v' makes 5 elastic collisions with a wall of container per second. The change in momentum of the wall per second in 5 collisions will be

A particle of mass '\(m\)' collides with another stationary particle of mass '\(M\)'. A particle of mass '\(\mathrm{m}\)' stops just after collision. The coefficient of restitution is

Force is applied to a body of mass \(2 \mathrm{~kg}\) at rest on a frictionless horizontal surface as shown in the force against time \((F-t)\) graph. The speed of the body after 1 second is

Two massless springs of spring constant \(\mathrm{K}_1\) and \(\mathrm{K}_2\) are connected one after the other forming a single chain, suspended vertically and certain mass is attached to the free end. If '\(e_1\)' and '\(e_2\)' are their respective extensions and '\(\mathrm{f}\)' is their stretching force, the total extension produced is

A mass '\(\mathrm{M}\)' moving with velocity '\(\mathrm{V}\)' along \(\mathrm{X}\)-axis collides and sticks to another mass \(2 \mathrm{M}\) which is moving along \(\mathrm{Y}\)-axis with velocity '\(3 \mathrm{~V}\)'. The velocity of the combination after collision is

A ball kept at \(20 \mathrm{~m}\) height falls freely in vertically downward direction and hits the ground. The coefficient of restitution is 0.4. Velocity of the ball first rebound is \(\left[\mathrm{g}=10 \mathrm{~ms}^{-2}\right]\)

A particle of mass '\(m\)' moving east ward with a speed '\(v\)' collides with another particle of same mass moving north-ward with same speed '\(v\)'. The two particles coalesce after collision. The new particle of mass '\(2 \mathrm{~m}\)' will move in north east direction with a speed (in \(\mathrm{m} / \mathrm{s}\) )

A simple spring has length \(l\) and force constant \(K\). It is cut in to two springs of length \(l_1\) and \(l_2\) such that \(l_1=n l_2\)(\(n\) is an integer). The force constant of spring of length \(l_1\) is

A person with machine gun can fire 50 g bullets with a velocity of \(240 \mathrm{~m} / \mathrm{s}\). A \(60 \mathrm{~kg}\) tiger moves towards him with a velocity of \(12 \mathrm{~m} / \mathrm{s}\). In order to stop the tiger in track, the number of bullets the person fires towards the tiger is

Consider the following statements \(\mathrm{A}\) and \(\mathrm{B}\). Identify the correct choice in the given answers.

A. In an inelastic collision, there is no loss in kinetic energy during collision.

B. During a collision, the linear momentum of the entire system of particles is conserved if there is no external force acting on the system.

A body falls on a surface of coefficient of restitution 0.6 from a height of \(1 \mathrm{~m}\). Then the body rebounds to a height of

A moving body with mass ' $\mathrm{m}_1$ ' strikes a stationary mass ' $\mathrm{m}_2$ '. What should be the ratio $\frac{m_1}{m_2}$ so as to decrease the velocity of first by (1.5) times the velocity after the collision?

1000 small balls, each weighing 1 gram, strike one square cm of area per second with a velocity $50 \mathrm{~m} / \mathrm{s}$ in a normal direction and rebound with the same velocity. The value of pressure on the surface will be

A particle of mass m collides with another stationary particle of mass $M$. The particle $m$ stops just after collision. The coefficient of restitution is