# Physics

A bullet moving with a speed 150 m/s strikes a tree and penetrates 3.5 cm before stopping. Find the magnitude of its acceleration and the time taken to stop.

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asked by Addie
1. Vf^2 = Vo^2 + 2ad = 0.

(150)^2 + 2a*3.5 = 0,
22500 + 7a = 0,
a = -3214.3m/s^2.

Vf = Vo + at = 0.
Solve for t and get:
t=(Vf-Vo)/a = (0-150) / -3214.3 = 0.0467s.

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posted by Henry
2. You didn't convert cm to m

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posted by Trevor
3. 32.14

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4. Wrong

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