# A small car meshes with a large truck in a head-on collision

1. Oct 17, 2008

### 12boone

1. The problem statement, all variables and given/known data

A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the average collision force is correct?
The truck experiences the greater average force.
>>> The small car experiences the greater average force.
The small car and the truck experience the same average force.
It is impossible to tell since the masses and velocities are not given.

Is this question right? I feel like a smaller object will have a greater force acting on it.

A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?
The total momentum both before and after the collision is 24 kg∙ m/s.
The total momentum before the collision is 24 kg∙m/s, and after the collision is 0 kg∙m/s.
>>>The total momentum both before and after the collision is zero.
None of the above is true.

would the velocity of the 6.0kg mass be negative?

2. Oct 18, 2008

### alphysicist

Re: Impulses

Hi 12boone,

Think about Newton's laws for this question. One of the laws directly answers this question.

Whether you call the left direction positive or negative is up to you; the important thing is that the velocity of the 6kg object will have the opposite sign as the velocity of the 4kg object, since they are in opposite directions.

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