Question

A 20 kg mass is flung at a velocity of 12 m/s. What is the kinetic energy of the object?

Answer 1

`\boxed {\boxed {\sf 1440 \ Joules}}`

Step-by-step explanation:

Kinetic energy can be found using this formula:

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

The mass is 20 kilograms and the velocity is 12 meters per second.

`m= 20 \ kg \\v= 12 \ m/s`

Substitute the values into the formula.

`E_k= (1)/(2) (20 \ kg)(12 \ m/s)^2`

Solve the exponent first.

• (12 m/s)²= 12 m/s * 12 m/s = 144 m²/s²

`E_k= (1)/(2) (20 \ kg)(144 \ m^2/s^2)`

Multiply the numbers in parentheses.

`E_k= (1)/(2) (2880 \ kg*m^2/s^2)`

Multiply by 1/2 or divide by 2.

`E_k=1440 \ kg*m^2/s^2`

• 1 kilogram square meter per square second is equal to 1 Joule.
• Our answer of 1440 kg*m²/s² is equal to 1440 J

`E_k= 1440 \ J`

The object's kinetic energy is 1440 Joules.