Question

A 26.0-g object moving to the right at 19.5 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.)

26.0-g object cm/s

11.0-g object cm/s

Answer 1

Let v1 be the initial velocity of 11g object = 15cm/s
and v1' be its final velocity = ?
Let v2 be the initial velocity of 26g object = 19.5cm/s
and v2' be its final velocity = ?

v1' = (m1 - m2)/(m1 + m2)*v1 + (2m2)/(m1 + m2)*v2
v1' = (11 -26)*15/(35) + (2x26)*19.5/35 = 22.54 cm/s

v2' = (2m1)/(m1 + m2)*v1 + (m2 -m1)/(m1 + m2)*v2
v2' = (2x11)*15/35 + (26 - 11)*19.5/35
v2' = 22*29/35 + 13*19/35
v2' = 17.78 cm/s

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velocity of 26.0-g object = 17.78 cm/s

velocity of 11.0-g object = 22.54 cm/s

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