The picture below shows a toy car in the process of rolling down a ramp. At point X, the kinetic energy is 50 Joules (J), and the potential energy is 30 J.
What is the total energy in the system once the car reaches the bottom of the ramp?
A
20 J, because the energy in the system cannot change form but can be created and destroyed
B
80 J, because the energy in the system can change form but cannot be created or destroyed
C
30 J, because the potential energy is the only energy at the bottom of the ramp
D
50 J, because the kinetic energy is the only energy at the bottom of the ramp
