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## Homework Statement

As part of a forensic experiment, a 50g bullet is fired horizontally into a 2.0kg wooden pendulum. The pendulum with the bullet embedded in it rises 15cm vertically from its initial position and stops.

a) Calculate the velocity of the block and bullet just after the collision.

b) What is the velocity of the bullet just before impact?

## Homework Equations

p = m*v

W = F*d = E

_{T}

Change in Eg = m*g*change in h

E

_{k}= 1/2*m*v

^{2}

Change in p = F*change in t

## The Attempt at a Solution

m

_{bullet}= 0.05kg

m

_{pendulum}= 2kg

In this case i think change in Eg = W in the up direction

m*g*change in h = W

_{up}

(2kg + 0.05kg)(9.8N/kg)(0.15m) = W

_{up}

3.0135N*m = W

_{up}

W

_{up}= Force

_{up}* displacement

_{up}

(3.0135N*m) / (0.15m) = Force

_{up}

20.09N = Force

_{up}

Change in p = F*change in t

Change in t = Vav/change in d

Therefore

p

_{up}= 20.09N * ((V

_{2}- V

_{1}) * 0.5)/0.15m

and here is where i'm lost.. This is part of an 8 question assignment sheet, i've finished the previous 7 but this one really has me stumped.

Would appreciate any help given asap since this is due monday.