A bullet with the mass of 45 g is fired into an 8.3 kg block of wood resting on a floor against a spring. This ideal spring (k = 76 N/m) has a maximum compression of 28 cm. What was the initial speed of the bullet?

Answer 1

what is the spring energy when compressed?
energy= 1/2 k * .28^2
what what the KE of the block and bullet? Same. What was then the velocity of the combination?
1/2 masstotal*v^2=1/2 k .28^2 solve for v.
But the law of conservation of momentum applied when the bullet hit the block:
massbullet*Vb=masstotal*Vabove
solve for Vb

Answer 2

THANK YOU. ;A;

Answer 3

I undergravd nothing IM 13