Determine the kinetic energy of a 1000-kg roller coaster car that is moving with a speed of 20.0m/s.

In this question all required information's are already provided. Based on these details the answer to the question can be easily determined. Let us now write down all the information's that are already given.
Mass of the roller coaster = 1000 kg
Velocity of the roller coaster = 20.0 m/s
We know the formula for finding the kinetic energy is
Kinetic energy = 0.5 * mass * (velocity) ^2
                       = 0.5 * 1000 * (20)^2
                       = 0.5 * 1000 * 400
                       = 200000 Joules
So the Kinetic energy of the roller coaster is 200000 joules.
 

The third and fourth box.