Question

Two cars collide on the parkway. The drivers are following too closely and the driver in the front slows because of traffic to a velocity of 20.0m/s and the driver behind is still moving at 30.0m/s, both cars traveling in the same direction in a rear end collision. If the cars are stuck together after the collision, how fast will they be traveling?

Answer 1

Answer:

The are moving with a speed of 25 m/s after the collision.

Explanation:

assuming the mass (m) of the cars are equal, let v = 20 m/s be the velocity of the driver in the front and u = 30 m/s be the velocity of the driver behind. let V be the velocity of the cars after the collision.

then, by conservation of linear momentum:

m×(v + u) = V×2×m

(v + u) = V×2

V = (v + u)/2

  = (20 + 30)/2

  = 25 m/s

Therefore, the are moving with a speed of 25 m/s after the collision.