How Fast Was Anna Driving Before the Collision?

[wonderclass07]

1. One early morning a young woman, Anna, left her home for work in a hurry. She didnt know how fast she was driving and she didn't see the stalled car on the street until she runs into it. When the copscame they determined that the two vihecles must have moved togather for about 2 meters distance at o.o5 m/s after collision. The mass of Anna's car is 300kg and the mass of the stalled car is 200kg. You are given this information to calculate how fast Anna was driving before collision



2. Is this kind of collision elastic or inelastic?



3. For some reason i fail to understand momentum problems. I would love to understand how to do this. Help!

 

[member 553083]

Momentum problems can be solved using the momentum equation, which states that the momentum of an object is equal to its mass times its velocity. Therefore, to solve a momentum problem, you will need to determine the mass and velocity of each object before and after the collision. Then, use the equation to calculate the total momentum before and after the collision and compare them. If the total momentum before and after the collision is the same, then the collision is said to be elastic. If the total momentum before and after the collision is not the same, then the collision is said to be inelastic. To solve the specific problem given above, we can use the momentum equation to calculate Anna's velocity before the collision: V1 = (m1v1 + m2v2)/m1 where m1 is the mass of Anna's car (300kg), v1 is the velocity of Anna's car before the collision (unknown), m2 is the mass of the stalled car (200kg), and v2 is the velocity of the stalled car before the collision (0). Plugging in the values, we get: V1 = (300*v1 + 200*0)/300 V1 = v1 Therefore, Anna's velocity before the collision was 0.05 m/s.