- #1

- 142

- 26

## Homework Statement:

- I don't understand what I'm doing wrong. When it comes to this problem

## Relevant Equations:

- Moment=velocity*mass

I have done question 1. But I'm struggling with the other one. So since the only thing I know about the rocket is the mass and the velocity, I guess I have to use momentum to solve this problem. From the first question, I found out that the x-velocity of the projectile is ##v_x=5 m/s*cos(30)=4,33 m/s##. I assume that the momentum of the projectile and the car is 0 before launching the projectile. So ##0=m_{projectile}*v_{projectile}+m_{car}*v_{car}=4,33m/s*1kg-5kg*v_{car}##. Then I get that ##v_{car}=0,866 m/s##. But in the solution I'm given the answer should be ##11,5 m/s##. What I'm a doing wrong?