A 0.015 kg marble moving to the right at 0.225 m/s makes an elastic head-on collision with a 0.03 kg shooter marble moving to the left at 0.18 m/s. After the collision, the smaller marble moves to the left at 0.315 m/s. What is the velocity of the 0.03 kg marble after the collision

0.135m/s

Explanation:

Using the law of conservation of momentum

m1u1+m2u2 = m1v1 +m2v2

m1 and m2 are the masses

u1 and u2 are the initial velocities

v1 and v2 are thee final velocities

Substitute the given parameters and get v2

0.015(0.225)+0.03(0.18) = 0.015(0.315)+0.03v2

0.003375+0.0054 = 0.004725 + 0.03v2

0.008775 - 0.004725 = 0.03v2

0.00405 = 0.03v2

v2 = 0.00405/0.03

v2 = 0.135m/s

Hence the final velocity of the 0.03kg marble after collision is 0.135m/s

at right angles to each other