- #1

Veronica_Oles

- 142

- 3

## Homework Statement

A hockey puck of mass 0.16kg has initial velocity of 2.0m/s[E] and collides with another puck that is initially at rest, has mass of 0.17kg. Once they collide the first puck travels 1.5m/s[N 31 E]. Find final velocity of second puck.

## Homework Equations

## The Attempt at a Solution

I keep getting an answer that does not match with solutions.

So I first drew it out then made a triangle that does is not a right angle, so I decided to use cosine law.

I am aware that my total momentum is 0.32 kg m/s because P

_{T}=P

_{T}' ...

P

_{T}= (0.16)(2)

=0.32 kg m/s

I also figured out my P

_{1}

P

_{1}= (0.16)(1.5)

= 0.24 kg m/s

I set my triangle up to have a 59° because 90°-31°.

Now I use cosine law to find opposite side of my 59°.

a=√(0.32)

^{2}+(0.24)

^{2}-2(0.24)(0.32)cos59

P

_{2}= 0.2844 kg m/s

Now I plug this into P=mv

V = 0.2844/0.17

V = 1.7m/s [E 46 S]

Did I do something wrong??