The x-component of the velocity of the third piece = -16.87 m/s

[aszymans]

Explosion of ball!

Homework Statement

An object with total mass mtotal = 16.6 kg is sitting at rest when it explodes into three pieces. One piece with mass m1 = 4.9 kg moves up and to the left at an angle of θ1 = 18° above the –x axis with a speed of v1 = 25.5 m/s. A second piece with mass m2 = 5.5 kg moves down and to the right an angle of θ2 = 23° to the right of the -y axis at a speed of v2 = 23.9 m/s.

What is the x-component of the velocity of the third piece

Homework Equations

I know the final P=0 and the mass of the third object = 6.2kg

The Attempt at a Solution

I tried finding the x component for m2 which I got to be 10.144 by tan(23)*23.9, and we know the x component of m1, so I multiplied these x components by their masses and added them, since P=0 I then subtracted them to the other side of the = sign to give me the opposite. I don't know if I am on the right track or not. I have tried every way I can think of to do this problem, can't get the right answer.

 

[ehild]

You are on the right track that the sum of the momentums is zero. Show your calculations in detail. I can not follow you from that you have. How do you get the x component of a vector?

ehild

 

[aszymans]

I was doing it wrong, and then I thought I was doing it correctly now, but am still getting the wrong answer. I am finding the x and y of each piece that we are given theta by taking the cos(theta)=x/v then found x(cm) by taking the x value and multiplying it mass then dividing by total mass, once I got both x's for both thetas given I found the difference between the two , I did this because I know P=0 so I want them to sum to 0, since I have one piece that goes in the negative x direction I made that negative and still can't figure out what I am doing wrong.

 

[ehild]

Write out the calculation with formulas. What are the x components of the momentum of both pieces?

ehild