Question

A 1750-kg car travels at 23 m/s when it crashes into the rear end of a 1500-kg car traveling at 20 m/s in the same direction on nearly frictionless ice. The two cars become stuck together and slide on the ice. How fast do the two cars move together immediately after the collision?

*use units*

Answer 1

21.6 m/s

Step-by-step explanation:

To solve this problem, we can use the principle of conservation of momentum. This principle states that the total momentum of a system remains constant unless an external force acts on it. In this case, the only external force acting on the system is the collision force between the two cars, which causes the cars to stick together and move as a single unit.

The initial momentum of the first car is 1750 kg * 23 m/s = 40250 kgm/s. The initial momentum of the second car is 1500 kg * 20 m/s = 30000 kgm/s. The total initial momentum of the system is 40250 kgm/s + 30000 kgm/s = 70250 kg*m/s.

After the collision, the two cars move together as a single unit, so the total mass of the system is 1750 kg + 1500 kg = 3250 kg. Since the total momentum of the system remains constant, the final velocity of the combined cars must be 70250 kg*m/s / 3250 kg = 21.6 m/s.

In summary, the two cars move together at a velocity of 21.6 m/s immediately after the collision.