Question

When cars are equipped with flexible bumpers, they will bounce off each other during low-speed collisions, thus causing less damage. In one such accident, a 1850 kg car traveling to the right at 1.50 m/s collides with a 1400 kg car going to the left at 1.10 m/s . Measurements show that the heavier car's speed just after the collision was 0.250 m/s in its original direction. You can ignore any road friction during the collision.
What was the speed of the lighter car just after the collision?

Answer 1

Answer:

0.55 m/s

Explanation:

Parameters given:

Mass of lighter car, m = 1400 kg

Mass of heavier car, M = 1850 kg

Initial speed of lighter car, u = -1.10 m/s (since it's moving to the left)

Initial speed of heavier car, U = 1.5 m/s

Final sped of heavier car, V = 0.25 m/s

Using the principle of conservation of momentum, total initial momentum is equal to total final momentum:

m*u + M*U = m*v + M*V

Inputting the values:

(1400 * -1.1) + (1850 * 1.5) = (1400 * v) + (1850 * 0.25)

-1540 + 2775 = 1400v + 462.5

1235 = 1400v + 462.5

1400v = 772.5

v = 772.5/1400

v = 0.55 m/s