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3 votes
A 4kg bird has 8 joules of kinetic energy, how fast is it flying?

User Mark Finch
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2 Answers

6 votes
i believe the answer is 2m/s
User Michael Wasser
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9.0k points
5 votes

Answer:

The bird is flying at a velocity of
v=2(m)/(s)

Step-by-step explanation:

You should use the equation for the kinetic energy, that is:


K_(E)=(1)/(2)mv^(2)

where
K_(E) is the kinetic energy, m is the mass of the bird and v is its velocity.

Solving for v:


mv^(2)=2K_(E)


v^(2)=(2K_(E))/(m)


v=\sqrt{(2K_(E))/(m)}

And replacing the values given in the problem you have:


v=\sqrt{(2*8J)/(4kg)}


v=\sqrt{(16J)/(4kg)}


v=\sqrt{4(m^(2))/(s^(2))}


v=2(m)/(s)

User Omarzouk
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