Question

How much thermal energy is created when a 3000 kg suv brakes to a stop from 20 m/s on a level road?

a. 1,200,000 J
b. 600,000 J
c. 60,000 J
d. 30,000 J
e. 90,000,000 J ​

Answer 1

b. 600,000 J

Step-by-step explanation:

Applying the law of conservation of energy,

The thermal energy created = Kinetic energy of the suv.

Q' = 1/2(mv²)............... Equation 1

Where Q' = Thermal energy, m = mass of the suv, v = velocity of the suv.

From the question,

Given: m = 3000 kg, v = 20 m/s

Substitute these values into equation 1

Q' = 1/2(3000×20²)

Q' = 600000 J

Hence the right option is b. 600,000 J