# Glancing Elastic Collison

**1. Two masses, m and M are involved in a glacing collision as seen below where θ and ø= pi/2.**

If M = nm what must n be such that the collision is elastic?

If M = nm what must n be such that the collision is elastic?

Remember if θ+ø=pi/2 then cos(θ)=sin(ø) and cos(ø)=sin(θ)

**2. I am suppose to find an number for n.**

**3. ∑KEo=∑KEf**

1/2m[itex]_{1}[/itex]v[itex]^{2}_{0}[/itex]+0=1/2m[itex]_{1}[/itex]v[itex]^{2}_{f1}[/itex]+1/2m[itex]_{2}[/itex]v[itex]^{2}_{f2}[/itex]

substitute m[itex]_{1}[/itex]n for m[itex]_{2}[/itex] and cancel the 1/2m[itex]_{1}[/itex]

v[itex]^{2}_{o1}[/itex]=v[itex]^{2}_{f1}[/itex]+nv[itex]^{2}_{f2}[/itex]

n=[itex]\frac{v^{2}_{o1}-v^{2}_{f1}}{v^{2}_{f2}}[/itex]

Not sure what to do from here please help. I know I’m probably suppose to use the θ and ø, but I’m not sure how to incorporate it.

**1. The problem statement, all variables and given/known data**

Known: M=nm, θ+ø=pi/2

Unknown: n

**2. Relevant equations**

W[itex]_{NC}[/itex]=ΔKE+ΔPE

KE=[itex]\frac{1}{2}[/itex]mv[itex]^{2}[/itex]

Momentum=∑p=mv[itex]_{f}[/itex]-mv[itex]_{o}[/itex]

**3. The attempt at a solution**

PS sorry I kinda messed this up it is my first post.

http://ift.tt/1tk60Cl

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