(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

If one bullet of mass 5 g that was moving to the right at speed 250 m/s at 20° above the horizontal collieded and fused with a 3 g bullet travelling to the left at speed 280 m/s at 15° above the horizontal, then what is their speed after impact?

3. The attempt at a solution

For the bullet of mass 5g

[tex]v_{xi}= 250 cos 20 = 234.9[/tex]

For the bullet of mass 5g

[tex]v_{xi}= 280 cos 15 = 270.4[/tex]

Since the question says "what is their speed after impact", I guess it means the collision is perfectly inelastic and they both stick together and travel to the same direction. In this case the EK before & after is not equal but momentum is conserved

Taking motion to the right as positive.

mv_{1ix}+mv_{2ix}=MV_{f}

[tex]\frac{3}{1000} 270.4 + \frac{5}{1000} \times -234.9= \frac{3+5}{1000}v_f[/tex]

But when I solve for v_{f}this doesn't produce the right answer. The correct answer has to be 93 m/s. Could anyone help me please?

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# Homework Help: Collision in midair

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