How do you find the initial speed?

AI Thread Summary
In the collision between a 2586 kg van and an 824 kg compact car at rest, momentum is conserved. The combined mass of the two vehicles moving together at 8.5 m/s allows for the calculation of the initial speed of the van. By applying the principle of conservation of momentum, the initial speed can be derived from the final momentum of the system. The discussion emphasizes the importance of understanding momentum in collision scenarios. Therefore, using the known masses and final velocity, the initial speed of the van can be determined.
Hannah :)
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2586 kg van runs into the back of a 824 kg compact car at rest. They move off together at 8.5 m/s. Assuming the friction with the road can be negligible, find the initial speed of the van.

i don't even know where to start :/
 
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Since they are colliding, what quantity do you know is conserved in collisions?
 
umm i don't know?
 
Hannah :) said:
umm i don't know?

Do you know anything about what mass*velocity gives?
 
yea it gives momentum
 
Hannah :) said:
yea it gives momentum

So in a collision, is momentum conserved or not?
 

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