Question

A 15 kg mass

moves with a
speed of 10
m/s. Calculate
the kinetic
energy.

Answer 1

`\boxed {\boxed {\sf 750 \ Joules}}`

Explanation:

Kinetic energy can be found using the following formula.

`E_k=(1)/(2)mv^2`

where m is the mass and v is the speed.

We know this is a15 kilogram mass moving with a speed of 10 meters per second. Therefore:

`m= 15 \ kg \\v= 10 \ m/s`

Substitute the values into the formula.

`E_k=(1)/(2)(15 \ kg)(10 \ m/s)^2`

Solve the exponent first.

• (10 m/s)²= 10 m/s* 10 m/s= 100 m²/s²

`E_k=(1)/(2)(15 \ kg)(100 \ m^2/s^2)`

Multiply 100 m²/s²and 15 kg.

`E_k=(1)/(2)(1500 \ kg*m^2/s^2)`

Multiply by 1/2 or divide by 2.

`E_k= 750 \ kg*m^2/s^2`

• 1 kilogram square meter per square second is equal to 1 Joule.
• Our answer of 750 kg*m²/s² is equal to 750 J

`E_k= 750 \ J`

The kinetic energy is 750 Joules.