Question

A 15 g toy car moving to the right at 22 cm/s

has a head-on nearly elastic collision with a
22 g toy car moving in the opposite direction
at 31 cm/s. After colliding, the 15g car moves
with a velocity of 42 cm/s to the left.
Find the speed of the second car after the
collision.
Answer in units of cm/s. Answer in units
of cm/s.

Answer 1

Step-by-step explanation:

The speed of the second car after the collision can be found using the law of conservation of momentum. The law states that the total momentum of a system remains constant if no external forces act on it.The initial momentum of the first car is (15g)(22 cm/s) = 330 g cm/s to the right.

The initial momentum of the second car is (22g)(-31 cm/s) = -682 g cm/s to the left.

The total initial momentum of the system is 330 g cm/s - 682 g cm/s = -352 g cm/sAfter the collision, the final momentum of the first car is (15g)(-42 cm/s) = -630 g cm/s to the left.

The final momentum of the second car is (m)(v) where m is the mass of the second car and v is the speed after the collision.

The total final momentum of the system is -630 g cm/s + (m)(v) = -352 g cm/s (since it remains constant)Therefore, m*v = -630 g cm/s + 352 g cm/s = -278 g cm/sTo find v, we need to divide the momentum by the mass

v = -278 g cm/s / 22 g = -12.6 cm/sSo the speed of the second car after the collision is -12.6 cm/s to the left.