SWJJ
moar bink ball
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A 1040-kg van, stopped at a traffic light, is hit directly in the rear by a 797-kg car traveling with a velocity of +3.50 m/s. Assume that the transmission of the van is in neutral, the brakes are not being applied, and the collision is elastic. What is the final velocity of (a) the car and (b) the van?
Ok so I have conservation of momentum and conservation of KE
so:
MvVv1 + McVc1 = MvVv2 + McVc2
The Vv1 is 0 so:
McVc1 = MvVv2 + McVc2
-McVc2 -McVc2
----------------------------------------------
Mc ( Vc1 - Vc2) = MvVv2
/Mv /Mv
so:
Vv2 = Mc/Mv (Vc1 - Vc2)
and I can sub Vv2in the KE conservation formula:
Mv(Vv1) ^2 + Mc(Vc1)^2 = Mv(Vv2)^2 + Mc(Vc2)^2
Vv1 = 0
so when I sub Vv2 what does that give me?
Ok so I have conservation of momentum and conservation of KE
so:
MvVv1 + McVc1 = MvVv2 + McVc2
The Vv1 is 0 so:
McVc1 = MvVv2 + McVc2
-McVc2 -McVc2
----------------------------------------------
Mc ( Vc1 - Vc2) = MvVv2
/Mv /Mv
so:
Vv2 = Mc/Mv (Vc1 - Vc2)
and I can sub Vv2in the KE conservation formula:
Mv(Vv1) ^2 + Mc(Vc1)^2 = Mv(Vv2)^2 + Mc(Vc2)^2
Vv1 = 0
so when I sub Vv2 what does that give me?