Question

by how many times will the kinetic energy of a body increaseif its speed is tripled? show by calculation.​

Answer 1

9 times

Step-by-step explanation:

Mass of a body remains constant.

Let the mass of a body be 'm'

Let the speed of the body be 'v'

Initial Kinetic Energy (K.E.) =
`(1)/(2) m {v}^(2)`

When speed is tripled , new speed = 3v

Mass of body = m (Mass is always constant)

Final Kinetic Energy (K.E.") =

`(1)/(2) * m * {(3v)}^(2)`

`= > (1)/(2) * m * 9v`

`= > 9( (1)/(2) m {v}^(2) )`

But we already know that
`k.e. = (1)/(2) m {v}^(2)`

Hence

`= > final \: k.e. = 9(initial \: k.e.)`