Question

A car with a mass of 1,500 kg doubles its speed from 50 km/h to 100 km/h. by how many times does the kinetic energy of the car increase

Answer 1

Step-by-step explanation:

To answer this question we only need to find the KE at both those velocities and then divide to find how many times the larger the larger one is than the smaller. The formula for KE is

`KE=(1)/(2)mv^2` and we will leave the velocity in terms of km/hr since it doesn't matter here (it just means that the unit is not J). Solving for the first KE:

`KE=(1)/(2)(1500)(50)^2` making this

KE = 1875000

The second velocity:

`KE=(1)/(2)(1500)(100)^2` making this

KE = 7500000

Dividing the larger by the smaller tells us that doubling the velocity makes the Kinetic Energy 4 times greater.