A ball with a mass of #13 kg# moving at #7 m/s# hits a still ball with a mass of #15 kg#. If the first ball stops moving, how fast is the second ball moving?

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Answer 1 · 2018-03-16T10:00:24

The velocity of the second ball is #=6.07ms^-1#

#m_1u_1+m_2u_2=m_1v_1+m_2v_2#

The mass the first ball is #m_1=13kg#

The velocity of the first ball before the collision is #u_1=7ms^-1#

The mass of the second ball is #m_2=15kg#

The velocity of the second ball before the collision is #u_2=0ms^-1#

The velocity of the first ball after the collision is #v_1=0ms^-1#

Therefore,

#13*7+15*0=13*0+15*v_2#

#15v_2=91#

#v_2=91/15=6.07ms^-1#

The velocity of the second ball after the collision is #v_2=6.07ms^-1#