Question

Elastic Collision problem

Answer 1

*final

Answer 2

for the first question
you need to use relative motion
the relative velocity of ball of mass m1 w.r.t. ball of mass m2= v1-v2
so the time taken is distance / speed
so t=s/v1-v2

next you need to use the equation of momentum conservation and the equation tht you will get from coefficient of restitution(e)
first momentum conservation(the cooolest)
pi=pf
so m1v1+m2v2=m1v'+m2v"
(i have assumed that both the masses go in the forward direction after collision with velocities v' and v" respectively)
next coefficient of restitution
here the collicion is elastic so e=1
so velocity of seperation/velocity of approach=1
so v1-v2/v"-v' = 1
so v1-v2=v"-v'
we've got the following equations
v1-v2=v"-v'
m1v1+m2v2=m1v'+m2v"
so by solving these equations, we get,
v'=(m1v1+m2v2)/(m1+m2)
and you can find v"
physics is truly based on nature
if you assume something, take the assumptions till the end and you'll get the correct answer
hope this helps

Answer 3

thanks! our prof nv thought abt that coefficient of restitution bt still put it in exams T^T can u help me with this too?