Important Physics Question

Question

A 12,000-kg truck and an 1,800-kg car are approaching a stop sign. The truck is moving with a velocity of 5 m/s and the car is moving at 2 m/s in the same direction. (Due to texting while driving) the truck collides with the rear end of the car. What is the velocity of the car immediately after the elastic collision? *

Hint: use the LOCOM equation for an elastic collision: m1v1 + m2v2 = m3v3 + m4v4

Answers to choose from:

1. 2.9 m/s
2. 4.3 m/s
3. 6.0 m/s
4. 8.0 m/s

Answer 1

Truck: M, v

Car: m, u

Mv₁ + mu₁ = Mv₂ + mu₂ ⇒

u₂ = [M(v₁ - v₂) + mu₁] / m = [12000(5 - 4.1) + 1800(2)] / 1800 m/s = 8.0 m/s