
Statement-1: In an elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed before the collision.
Statement-2: In an elastic collision, the linear momentum of the system is conserved.


Important Questions on Centre of Mass, Momentum and Collisions

Look at the drawing given in the figure which has been drawn with ink of uniform line-thickness. The mass of ink used to draw each of the two inner circles, and each of the two line segments isThe mass of the ink used to draw the outer circle is The coordinates of the centres of the different part are: outer circle left inner circleright inner circle vertical lineand horizontal lineThe y-coordinate of the centre of mass of the ink in this drawing is

Two small particles of equal masses start moving in opposite directions from a point in a horizontal circular orbit. Their tangential velocities are respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at these two particles will again reach the point


A ball of mass rests on a vertical post of height A bullet of mass travelling with a velocity in a horizontal direction, hits the centre of the ball. After the collision, the ball and bullet travel independently. The ball hits the ground at a distance of and the bullet at a distance of from the foot of the post. The initial velocity of the bullet is


A block of mass has a circular cut with a frictionless surface as shown. The block rests on the horizontal frictionless surface of a fixed table. Initially the right edge of the block is at in a coordinate system fixed to the table. A point mass m is released from rest at the topmost point of the path as shown and its slides down. When the mass loses contact with the block, its position is x and the velocity isAt the instant, which of the following options is/are correct ?

A circular disc of radius is removed from a bigger circular disc of radius such that the circumferences of the discs coincide. The centre of mass of the new disc is from the centre of the bigger disc. The value of α is.
