{{}} A white ball of mass 1.0 kg moving with initial speed u = 0.5 m s^-1 collides with stationary red ball of same mass, they move forward making angle of 90° between their paths. Their speed is A)1 m s^-1 B)0.354 m s^-1 C)2 m s^-1 D)3 m s^-1

Question

Quizplus · Accepted Answer

Since the collision conserves momentum and the masses are equal, the initial momentum of the system is equal to the combined momentum of the two balls after the collision. Given that the balls move at 90° to each other after the collision, their velocities can be treated as components of a right-angled triangle where the hypotenuse represents the initial velocity of 0.5 m/s. Using Pythagoras' theorem, each side (velocity of each ball) is found to be 0.354 m/s, as $v = \frac{0.5}{\sqrt{2}}$.

{{}} a White Ball of Mass 1