Question

A car traveling at 60 mph has how much more energy than a car going at 20 mph? K.E. increases by a factor of there is no increase in KE 3 times 9 times impossible to tell because the mass of the car is unknown

Answer 1

Answer:

Assuming that the masses of the cars are the same

9 times

Explanation:

Kinetic energy can be computed using the formula:

$KE = \dfrac{mv^{2}}{2}$

Where:

KE = Kinetic energy

m = mass

v = velocity

As you can see in your problem, the velocity of the the first car mentioned is 3 times faster.

Looking at the the formula, velocity is raised to two (2). So if we put it in terms of equations this is how it will look:

Let v = velocity of the slower car

Car 1: velocity = (3v)

$KE=\dfrac{mv^{2}}{2}$

$KE=\dfrac{(m)(3v)^{2}}{2}$

$KE=\dfrac{(m)9v^{2}}{2}$

The increase is by a factor of 9.