Question

Two cars have a ‘rear end’ collision. A 1500 kg Honda CRV moving at 20 m/s strikes a 1200 kg Ford moving at 15 m/s. Don’t worry, the Honda CRV is not Mr. Warren’s. After the collision the bumpers become locked and they continue to move as one mass. What is their velocity after the crash?

Answer 1

Step-by-step explanation:

To solve this problem, we can apply the principle of conservation of momentum. According to this principle, the total momentum of a closed system remains constant before and after a collision.

The initial momentum of the system is given by the sum of the individual momenta of the Honda CRV and the Ford:

Initial momentum = (mass of Honda CRV) * (velocity of Honda CRV) + (mass of Ford) * (velocity of Ford)

= (1500 kg) * (20 m/s) + (1200 kg) * (15 m/s)

To find the velocity of the cars after the collision, we need to consider that they become locked and move as one mass. Let's denote the final velocity of the combined mass as V.

The final momentum of the system is then given by the total mass (sum of the masses of both cars) multiplied by the final velocity:

Final momentum = (mass of Honda CRV + mass of Ford) * (final velocity)

= (1500 kg + 1200 kg) * V

According to the conservation of momentum principle, the initial momentum and the final momentum should be equal:

Initial momentum = Final momentum

(1500 kg) * (20 m/s) + (1200 kg) * (15 m/s) = (1500 kg + 1200 kg) * V

Now we can solve for V:

(1500 kg) * (20 m/s) + (1200 kg) * (15 m/s) = (2700 kg) * V

(30000 kg·m/s) + (18000 kg·m/s) = (2700 kg) * V

48000 kg·m/s = (2700 kg) * V

V = (48000 kg·m/s) / (2700 kg)

V ≈ 17.78 m/s

Therefore, the velocity of the combined mass after the collision is approximately 17.78 m/s.