Question

A 1300 kg aircraft going 40 m/s collides with a 3000 kg aircraft that is parked and they stick together after the collision. If they skid for 157.1 m in 25 s before stopping, how fast were the two stuck-together aircraft going immediately after the collision? Hint: Are the aircraft moving at a constant velocity after the collision or do they experience an acceleration?

Answer 1

From the given question,

Mass of first aircraft(m)=1300 kg

Initial velocity of first aircraft(u)=40 m/s

Mass of second aircraft(M)=3000 kg

Initial velocity of second aircraft(U)=0 m/s

After collision

Combined mass=(m+M)= 1300+3000=4300 kg

Distance travelled(s)=157.1 m

Time(t)=25 s

final velocity=0 m/s

using conservation of momentum

mu+MU= (m+M)V

1300*40+3000*0=4300*V

V=12.1 m/s

The two stuck-together aircraft were going at velocity of 12.1 m/s immediately after the collision.

The aircraft experience negative acceleration after the collision.