Help with a conservation of momentum problem

AI Thread Summary
The discussion revolves around calculating the recoil velocity of a rifle when a bullet is fired. A 15 g bullet is shot at 220 m/s from a 6.5 kg rifle, and the conservation of momentum principle is applied. The user correctly notes that the initial velocity is zero, leading to the equation: Mass of the gun times its velocity plus mass of the bullet times its velocity equals zero. The user calculated a recoil velocity of -0.22 m/s after converting the bullet's mass to kilograms, confirming that standard units should be used. The conversation emphasizes the importance of using proper units in physics calculations.
tommyboy2
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A 15 g bullet is fired is fired with a velocity of 220 m/s from a 6.5 kg rifle. What is the recoil velocity of the rifle?

That is the problem

I think i use the formula...

This half of the equation equals zero due to the initial velocity equaling zero = Mass of the gun*Velocity of the gun + Mass of the bullet*Velocity of the bullet

I ended up getting -.22 m/s

i converted the 15 g to kilograms I was not sure if it should have been grams or kilograms for this problem

Any help I would be greatful.
 
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tommyboy2 said:
This half of the equation equals zero due to the initial velocity equaling zero = Mass of the gun*Velocity of the gun + Mass of the bullet*Velocity of the bullet
That's good.

I ended up getting -.22 m/s
Show how you got that answer.

i converted the 15 g to kilograms I was not sure if it should have been grams or kilograms for this problem
Standard units for mass would be kilograms.
 
Alright thanks I thought that was the correct formula, what i was not sure about was the units thanks.
 

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