I have this problem. In the before(före)pic the box m is about to collide with the left 2m box. After the first collision the m box bounces back and collides with the 2m box to the right. My task is to calculate the speed of m+2m aftre they move togheter
the first collision is completely elastic and the second is completely inelastic.
The thing is thats just 2 easy calculations and I get the result that the end speed of m+2m is v/6(v is the begining speed of the m block before any collision). m offocurse represents mass.
Our proffesor most often gives us insanely tricky task and this one seems to easy. Am I missing something?
first I did this calculation
Vx=v*(m-2m)/(m+2m)=v*(-m)/(3m)=-v/3
Vx is speed of the m block after first collision
then I did this to calculate speed of m+2m after second collision.
I changed the direction of the x-axis btw to get a positive value of Vx
I used this
mAvA + mBvB=(mA+mB)V2
mA=m vA=Vx mB=2m and vB=0
so I have V2= (mVx)/(m+2m) and because Vx=v/3 I get =>
V2= (v/3)*(1/3)=v/6
So the answere is v/6. Does this look right?
Reply With Quote