Question

A 1000-kg aircraft going 25 m/s collides with a 1500-kg aircraft that is parked. They stick together after the collision and are moving at 10 m/s. If they skid for 30 seconds before stopping, how far (in meters) did they skid?

Hint: Are the aircraft moving at a constant velocity after the collision or do they experience an acceleration?

Answer 1

if acceleration is constant their average speed during the stop
= 10/2 = 5 m/s
5 m/s * 30 s = 150 meters

Answer 2

Motion is accelerated cause it says "If they skid for 30 seconds before stopping".

1) One should use a = Vf - Vo / t in order to find acceleration.
2) Then use d= vf^2 - Vo^2 / 2a in order to find acceleration.

1) As Vo = 10 m/s; Vf = 0 m/s and t = 30 s then a = -0.333
2) Using the former values, d = 150.15 m (rounded a = -0.333)
*Employing all decimals d = 150 m