Two balls of different masses collide head on . After the collision, the ball sremain at rest, and no external force act on them. Which statements is true about the speed of the balls before at the collision ?

A 2.5-kg ball and a 5.0-kg ball have an elastic collision. Before the collision, the 2.5-kg ball was at rest and the other ball had a speed of 3.5 m/s. What is the kinetic energy of the 2.5-kg ball after the collision?

A smooth ball 'A' moving with velocity 'V' collides with another smooth identical ball at rest. After collision both the balls move with same speed with angle between their velocities 60^(@) . No external force acts on the system of balls. The speed of each ball after the collision is

A smooth ball 'A' moving with velocity 'V' collides with another smooth identical ball at rest. After collision both the balls move with same speed with angle between their velocities 60^(@) . No external force acts on the system of balls. The speed of each ball after the collision is

A ball moving with a speed of 9ms^(-1) strikes an identical ball such that after the collision the direction of each ball makes and angle 30^@ with the original line of motion. Find the speeds of the two balls after the collision.

A ball moving with a velocity of 12ms^(-1) collides with another identical stationary ball . After the collision they move as shown in figure . Find the speed of the balls after the collision . Also , decide whether the condition is elastic or not .

A ball moving with a speed of 9m//s strikes an identical ball at rest, such that after the collision, the direction of each ball makes an angle of 30^(@) with the original line of motion. Find the speeds of the two balls after collision.