Answer:
Truck's speed = 5.21 m/s
Car's speed = 20.2 m/s
Explanation:
Given:
Mass of truck = M = 1650 kg
Speed of the truck initially = U = 15 m/s
Mass of the car = m = 779 kg
Initial speed of the car =u = 0
From the momentum conservation, Total initial momentum = Total final momentum.
M V+m U = M V +m v
⇒ (1650)(15) + 779×0 = (1650)V + 779 v
⇒ 24750 = 1650 V+779 v →(1)
Since the collision is elastic, relative velocity of approach = relative velocity of separation. 15 = v - V
⇒ v =V + 15; This is now substituted in the equation(1) above.
24750 = 1650 V + (799) (V+15)
⇒ 24750 = 1650 V + 799 V + 11985
⇒ 2449 V = 12765
⇒ Final velocity of the truck = [tex]\frac{12765}{2449}[/tex] = 5.21 m/s
Final velocity of the car = v = V+15 = 5.21 + 15 = 20.2 m/s
