Two gliders on an air track collide in a perfectly elastic collision. Glider A has mass 1.1 kg and is initially

Question

travelling at a velocity of 2.7 m/s [E]. It collides head-on with glider B with mass 2.4 kg, travelling at a
velocity of 1.9 m/s [W]. Determine the final velocity of glider B using elastic collision formulas.

Answer 1

Momentum before = Momentum after:
M1*V1 + M2*V2 = M1*V3 + M2*V4.
1.1*2.7 + 2.4*(-1.9) = 1.1*V3 + 2.4*V4,
1.1*V3 + 2.4*V4 = -1.59.

Conservation of KE Eq:
V3 = (V1(M1-M2) + 2M2*V2)/(M1+M2).
V3 = (2.7(1.1-2.4) + 4.8*(-1.9))/(1.1+2.4) = -3.61 m/s = 3.61 m/s, west = Velocity of glider A after the collision.