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The two toy cars shown in the figure, with masses as given in the figure, are ready to race. Both cars begin from rest. For each question, state whether the correct answer is car A, car B, or whether the two cars have equal values for the parameter in question.

For the next three parts assume that the carsâ€™ motors supply the same force to each car over the course of a 1.0-meter race.

Car A mass= 1000g

Car B mass= 800g

I know that A) Which car crosses the finish line 1.0 away first?

=> Car B wins because it has less mass and more acceleration therefore more force.

B) Which car has the larger kinetic energy when it crosses the finish line 1.0 away?

=> Both cars have the same kinetic energy I know that both cars have the same kinetic energy because is a scalar , it does not depend in any other variable than energy. So they both have the same amount of kinetic energy.

C) Which car has a larger momentum when it crosses the finish line 1.0 away?

=> Car A because car A has a greater mass than car B they both have the same speeds therefore car A it will have more momentum.

D) Which car has traveled farther after 10^8 ?

=> Car B (I really don't get this one) (or why)

E) After 10^8 which car has a larger kinetic energy?

=> Car B (I really didn't understand this one nether)

F) After 10 which car has a larger momentum?

=> Both cars have the same momentum. (I don't know why both have the same momentum when they both have different masses and same velocity.)

Help? Can someone explain this to me?? please??

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# Homework Help: Kinetic energy and momentum (Conceptual Question)

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