Question

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

Answer 1

i believe the answer is 2m/s

Answer 2

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)`