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Hatshy [7]
3 years ago
5

The power needed to accelerate a projectile from rest to its launch speed v in a time t is 42.0 W. How much power is needed to a

ccelerate the same projectile from rest to a launch speed of 2v in a time of t?
Physics
1 answer:
ExtremeBDS [4]3 years ago
7 0

Answer:168 W

Explanation:

Given

Power needed P=42 W

initial Launch velocity is v

Energy of projectile when it is launched E=\frac{1}{2}mv^2

Power=\frac{Energy}{time}

Power=\frac{E}{t}

42=\frac{\frac{1}{2}mv^2}{t}--------1

Power when it is launched with 2 v

E_2=\frac{1}{2}m(2v)^2=\frac{4}{2}mv^2

P=\frac{2mv^2}{t}---------2

Divide 1 & 2 we get

\frac{42}{P}=\frac{1}{2\times 2}

P=42\times 4=168 W    

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