A 1.0x10^5 N truck moving at a velocity of 15 m/s north collides head-on with a 1.0x10^4 N car moving at a velocity of 25 m/s south. If they stick together upon impact, what is the velocity of the combined masses?

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Answer 1 · 2018-08-04T22:10:16

I tried this:

We can use concervation of momentum before and after the impact:
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We write:

#m_1v_1+m_2v_2=(m_1+m_2)V#

rearrange:

#V=(m_1v_1+m_2v_2)/(m_1+m_2)=((1xx10^5*15)+(1xx10^4*(-25)))/(1xx10^5+1xx10^4)=11.4m/s#

(positive, to the right)