Question

Suppose a moving car has 2000 J of kinetic energy. If the carʹs speed doubles, how much kinetic energy would it then have?

A) 8000 J
B) 6000 J
C) 1000 J
D) 4000 J
E) 2000 J

Answer 1

option A

Step-by-step explanation:

given,

Kinetic energy of the car = 2000 J

speed of the car is doubled

we know,

`KE_1 = (1)/(2)mv^2`

`2000= (1)/(2)mv^2`........(1)

now, speed of the car is doubled

v' = 2 v

`KE_2 = (1)/(2)mv'^2`

`KE_2 = (1)/(2)m(2v)^2`

from equation (1)

`KE_2 = 4* (1)/(2)m(v)^2`

`KE_2 = 4* 2000`

`KE_2 = 8000\ J`

Hence, the Kinetic energy would be equal to 8000 J.

The correct answer is option A.