If a roller-coaster car has 40,000 J of gravitational potential energy when at rest on the top of a hill, how much kinetic energy does it have when it is ½ of the way down the hill?

Work Shown:

PE = potential energy

KE = kinetic energy

m = mass

g = acceleration of gravity

h = height of the object

PE = m*g*h = 40,000 joules

If the car is halfway down the hill, then that means the height of the car is h/2 instead of h

We can then say:

m*g*(h/2) = (m*g*h)/2 = (40,000)/2 = 20,000 J

is the amount of potential energy at this location. The amount of kinetic energy must be the remaining amount that adds to this, to get 40,000 J again.

Put another way: The 40,000 J of PE to start off with, when KE = 0, means we have a total energy of 40,000 J

So,

PE+KE = total energy

PE+KE = 40,000 J

20,000 J + KE = 40,000 J

KE = (40,000 J) - (20,000 J)

KE = 20,000 J when the car is halfway down the hill.

the answer is kevlar

as we know our atmosphere or air have different levels. every level has other gasses, and every gas has another permeability. when the light comes from lower permeability to higher permeability, it changes its direction. so that means that when the light comes from the moon to the earth, it changes it's direction many more times. it basically means that the shape of the light part of the moon is changed on the earth.

hope this ! this is not copied! search it up, it's free of plagiarism!