Question

A 27.0-g object moving to the right at 21.5 cm/s overtakes and collides elastically with a 11.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. (Take the positive direction to be to the right. Indicate the direction with the sign of your answer.)

Answer 1

Answer:

final speed of the first object: 17.73 cm/s

final speed of the second object: 24.23 cm/s

Explanation:

Data:

mass of the first object, m1 = 27.0 g

mass of the second object, m2 = 11.0 g

initial speed of the first object, v1i = 21.5 cm/s

initial speed of the second object, v2i = 15 cm/s

final speed of the first object, v1f = ? cm/s

final speed of the second object, v2f = ? cm/s

Elastic collisions formula:

v1f = (m1 - m2)/(m1 + m2) * v1i + 2*m2/(m1 + m2) * v2i

v1f = (27 - 11)/(27 + 11) * 21.5 + 2*11/(27 + 11) * 15

v1f = 17.73 cm/s

v2f = 2*m1/(m1 + m2) * v1i + (m2 - m1)/(m1 + m2)*v2i

v2f = 2*27/(27 + 11) * 21.5 + (11 - 27)/(27 + 11)*15

v2f = 24.23 cm/s