Mechanical Energy At what point on the rollercoaster is
the kinetic energy the highest?
A. point A
B. point B
C. point C
D. cannot be determined
with the information provided.

Point C

Explanation:

Remember that kinetic energy is energy a object has when it's in motion so the higher the speed, the higher the kinetic energy is. In this case we have a roller coaster, as the roller coaster goes up the tracks it's kinetic energy is low because it slows down as it climbs to the top of the hill. Then as it sits on top of the hill it's kinetic energy is little to none before it goes down the hill because the roller coaster isn't in motion. As when the roller coaster goes down the hill it's speed increases meaning the kinetic energy increases which means option C or "point C" is your answer.

Hope this helps.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.