Question

A car is moving at 68 miles per hour. The kinetic energy of that car is 5 × 10 5 J.How much energy does the same car have when it moves at 97 miles per hour?

Answer 1

The car has an energy of 1.017 × 10⁵ J when it moves at 97 miles per hour

Step-by-step explanation:

Given the data in the question;

Initial velocity v₁ = 68 miles per hour = 30.398 meter per seconds

let mass of the car be m

kinetic energy of that car is 5 × 10⁵ J

so

E₁ =
`(1)/(2)`mv²

we substitute

5 × 10⁵ =
`(1)/(2)` × m × ( 30.398 )²

5 × 10⁵ =
`(1)/(2)` × m × ( 30.398 )²

5 × 10⁵ = m × 462.019

m = 5 × 10⁵ / 462.019

m = 1082.2065 kg

Now, Also given that; v₂ = 97 miles per hour = 43.362 meter per seconds

E₂ =
`(1)/(2)`mv₂²

we substitute

E₂ =
`(1)/(2)` × 1082.2065 × ( 43.362 )²

E₂ =
`(1)/(2)` × 1082.2065 × 1880.263

E₂ = 1.017 × 10⁵ J

Therefore, The car has an energy of 1.017 × 10⁵ J when it moves at 97 miles per hour