Question

Ball 1, with a mass of 10kg, is moving to the right at 20 m/s. Ball 2 is moving to the left at 20 m/s. Upon collision, ball 2 comes to a standstill and ball 1 moves to the left at twice its original speed. What is the mass of ball 2?

ok I know the answer is 30kg because I guessed on the experiment and it was right. I'm just not sure what formula I need to get there? And the formulas confuse me a lot anyway

Answer 1

@Directrix are you good with physics?

Answer 2

@Callisto

Answer 3

Please, note that you have to apply the law of conservation of momentum. Now before collision, total momentum of your system is:
\[m _{2}v _{2}-m _{1}v _{1}\]
and after collision total momentum of your system is:
\[2m _{1}v _{1}\]
please equate those values each other, and you will find an equation, then solve that equation for m_2

Answer 4

I don't understand

Answer 5

please, soplve this equation for m_2:
\[m _{2}v _{2}-m _{1}v _{1}=2m _{1}v _{1}\]
where m_1=10, v_1=20 and v_2=20

Answer 6

oops...solve this equation...