Elastic collision between 2 different masses

[Yeldarb]

Homework Statement

See picture

Homework Equations

p = p1 +p2
p = mv

The Attempt at a Solution

See picture, using equations for the velocity and using 90-tan-1(2) for the angle

 

[ehild]

Do not forget that momentum is a vector quantity. Both of its components are conserved.
Why do you think that θ₂=90-tan^-1(2)?

 

[Yeldarb]

Do not forget that momentum is a vector quantity. Both of its components are conserved.
Why do you think that θ₂=90-tan^-1(2)?

Does this mean that I need to use a px and a py equation? Does what I got help me at all? The picture shows tan(theta1)=2, so theta1= tan-1(2) and since the angle between the two should be 90, 90-theta1 =theta2

Thanks

 

[SammyS]

Does this mean that I need to use a px and a py equation? Does what I got help me at all? The picture shows tan(theta1)=2, so theta1= tan-1(2) and since the angle between the two should be 90, 90-theta1 =theta2

Thanks

What makes you think the angle between their directions is 90° ?

 

[ehild]

Does this mean that I need to use a px and a py equation? Does what I got help me at all? The picture shows tan(theta1)=2, so theta1= tan-1(2) and since the angle between the two should be 90, 90-theta1 =theta2

Thanks

Yes, you need an equation for px and an other one for py. NO, the two angles do not add up to 90°. It happens if the two masses are equal.