(adsbygoogle = window.adsbygoogle || []).push({}); Bullet speed- Please Help!

I am not to great at physics and I was hoping someone could point me where I am going wrong in this problem! :) My answer I came up with is 2.5 m/s but that isn't one of my options so I know something has to be off.

5. To find the speed with which a gun fires bullets, a bullet of mass 5 gm is fired horizontally into a 10 Kg block of wood resting on a frictionless table. The bullet gets embedded in the block and the block is found to have a velocity of 0.5 m/s after collision. What is the speed of the bullet?

Bullet Speed= 2.5 m/s

Mv1i + 0 = (m +M)V

Mv1i + 0 = (5gm +10 kg) .5 m/s

m1 u1 + m2 u2 = (m1 + m2) V

(5gm u1) + (10kg *0m/s) = (5gm + 10kg) .5m/s

(5gm u1) + (0) =7.5

u1 = 2.5 m/s

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# Homework Help: Bullet speed-

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