Question

Two gliders on an air track collide in a perfectly elastic collision. Glider A has a mass of 1.1 kg and is initially travelling at a velocity of 2.7 m/s [E]. It collides head-on with glider B with a mass of 2.4 kg, travelling at a velocity of 1.9 m/s [W]. Determine the final velocity of glider A.

Answer 1

m1= mass 1 = 1.1 kg

Vi1 = initial velocity 1 = 2.7 m/s

m2= 2.4 kg

V2i = -1.9 m/s

We assume east as positive and west as negative.

Apply the formulas:

Vf1 = ?

`vf1=((m1-m2)/(m1+m2))Vi1+((2m2)/(m1+m2))Vi2`

Replacing:

`Vf1=((1.1-2.4))/((1.1+2.4))2.7+((2*2.4))/((1.1+2.4))-1.9`
`Vf1=((-1.3)/(3.5))2.7+((4.8)/(3.5))-1.9`
`Vf1=-1-2.6=-3.6\text{ m/s}`

Answer: 3.6 m/s west