Question

A pinball bangs against a bumper giving the ball a speed of 42cm/s if the ball has a mass of 50.0g what is the ball’s kinetic energy in joules

Answer 1

Step-by-step explanation:

Given:-

mass=50g

velocity=42cm/s

To find:-

Kinetic energy

Solution:-

As we know that

`{\boxed{\sf kinetic\:energy={\frac {1}{2}}mv^2}}`

• Substitute the values

`{:}\longrightarrow`
`\sf k.v={\frac {1}{{\cancel{2}}}}* 50* {\cancel{42}}^2`

`{:}\longrightarrow`
`\sf k.v=50* 21^2`

`{:}\longrightarrow`
`\sf k.v=50×441`

`{:}\longrightarrow`
`\sf k.v=22050MJ`

• 1Joule=1000milijoules
• 22050MJ=
  `{\frac {22050}{1000}}=22.05J`
• =22J(Approximately)

`\therefore`
`{\underline{\boxed{\bf Kinetic\:energy=22Joule}}}`