If a rock falls from a cliff at what point are its kinetic and potential energy the same? ignore air resistance. assume gravitational energy is relative to the bottom of the cliff. a. just as it starts to fall
b. halfway down
c. just before it hits the bottom
d. never
e. always​

speed

ratio of distance traveled to time interval

net force

vector sum of forces on object

object

source of diverging light rays either luminous or illuminated

don't remove my answer im trying my best to answer them

explanation:

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.