# IDENTICAL TRUCK COLLISIONS

## Homework Statement

Two identical trucks traveling at different constant speeds are about to collide. The trucks are traveling in opposite directions with truck A going at a velocity of 3m/s right and truck B going at 4m/s left.

During the collision, will the magnitude of the acceleration of truck A be (a) greater than, (b) equal to, or (c) less than the magnitude of the acceleration of truck B?

## The Attempt at a Solution

I thought the answer would be (b) equal to, since they both travel at a constant velocity, but then I realised that during the collision they would be decelerating and so I think that it would be (c) less than, since truck A is going at a slower velocity than truck B and so it would decelerate less.

Can anyone tell me if I'm right or wrong and explain why? thanks

gneill
Mentor
What type of collision is being considered, elastic or inelastic? If elastic they will both move with different velocities after the collision. Of inelastic, they will both move off together at the same velocity.

Edit: Actually, I might suggest that you ponder the effects that Newton III will dictate for this collision (regardless of the type).

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What type of collision is being considered, elastic or inelastic? If elastic they will both move with different velocities after the collision. Of inelastic, they will both move off together at the same velocity.

Edit: Actually, I might suggest that you ponder the effects that Newton III will dictate for this collision (regardless of the type).
Yea I think it's talking about the effects of Newton 3 since that's what we've covered in the lesson. But I am still unsure of how that relates to the magnitude of accelerations. Equal but opposite forces, so would they have the same acceleration?

gneill
Mentor
Yea I think it's talking about the effects of Newton 3 since that's what we've covered in the lesson. But I am still unsure of how that relates to the magnitude of accelerations. Equal but opposite forces, so would they have the same acceleration?
Yes. They have identical masses and the forces are always of the same magnitude. What does Newton II say about forces, masses, and acceleration?