Answer:
he lower part of the curve N = M (g + v² / r)
upper part of the curve N = m (v² /r -g)
Explanation:
In a roller coaster there is a long climb that allows the car to acquire gravitational potential energy, when this energy is converted into kinetic energy, there is a raven, in these curves we have two parts the lower part, where you have a feeling of great weight and another in the upper part where you have a feeling of weightlessness.
These sensations can be explained using Newton's second law, let's apply it to the lower part of the curve
N-W = m a
acceleration is centripetal
a = v² / r
we substitute
N = mg + m v² / r
N = M (g + v² / r)
In this part the apparent weight is increased by the speed of the body squared, it feels like a lot of fart.
In the upper part of the curve the force of gravity continues to act downwards, the normal that is the reaction of the surface also goes downwards, the centripetal acceleration pointing towards the center of the curve has a vertical downward direction
-N -W = -m a
N = ma -W
N = m (v² / r -g)
In this case we see that the normal that gives the sensation decreases, which is why we feel a loss of weight, in the case of v2 / r = g, the request is total and the sensation of weightlessness.