Conservation of momentum of a boxcar

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In a completely inelastic collision, a 9700 kg boxcar traveling at 18 m/s collides with a stationary second car, resulting in both moving together at 8.0 m/s. To find the mass of the second car, the conservation of momentum principle is applied. The initial momentum of the boxcar is calculated, and the final momentum of both cars is set equal to this initial momentum. The formula P=mv is used to derive the mass of the second car. The discussion emphasizes the importance of using correct significant figures in calculations.
kmax12
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A 9700 kg boxcar traveling at 18 m/s strikes a stationary second car. The two stick together and move off with a speed of 8.0 m/s. What is the mass of the second car?



p=ma



is 21825 m/s the answer? sig figs?
 
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its asking for mass...
 
Ok, so this is an example of completely inelastic collision- that means that the 2 bodies will have the same final velocity. Use the formula for the final velocity, and find the mass of the car. Did that help?
 
P=mv

P = momentum, m=mass, v=velocity...
 

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