Question

A car moving with a velocity of 20 meters/second has

1.8 * 105 joules of kinetic energy. What is the mass of the car?

Answer 1

Explanation :

Given that,

Velocity of the car, v = 20 m/s

Kinetic energy of the car,
`E_k=1.8* 10^5\ J`

Kinetic energy is given by :

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

`m=(2E_k)/(v^2)`

So,
`m=(2* 1.8* 10^5\ J )/((20\ m/s)^2)`

m = 900 kg

Hence, the mass of the car is 900 kg

Answer 2

Kinetic energy is the product of mass and the square of the velocity of the moving object. In this case, we substitute the given data, that is 1.8 x10^5 joules = m * (20 m/s2)^2. Extracting the mass, the mass of the car therefore is equal to 450 kg