Question

A 1250 kg car, driving 7.39 m/s, runs into the back of a stationary 5380 kg truck. After the collision, the truck moves forward at 2.30 m/s. What is the final velocity of the car?

Answer 1

The answer is -2.5 I just did this question so I can assure you it is correct the issue the previous answer had was it lacked the mention of directions which is why he left the answer positive when it should have been negative.

Step-by-step explanation:

Answer 2

Step-by-step explanation:

Given that,

Mass of the car, m₁ = 1250 kg

Initial speed of the car, u₁ = 7.39 m/s

Mass of the truck, m₂ = 5380 kg

It is stationary, u₂ = 0

Final speed of the truck, v₂ = 2.3 m/s

Let v₁ is the final velocity of the car. Using the conservation of momentum as :

`m_1u_1+m_2u_2=m_1v_1+m_2v_2`

`1250* 7.39+5380* 0=1250* v_1+5380* 2.3`

`v_1=-2.5\ m/s`

So, the final velocity of the car is 2.5 m/s but in opposite direction. Hence, this is the required solution.