# Circular motion and Net force

• ShizukaSm
In summary, In the chapter on conservation of energy, the book explains that the theory can be used to find the velocity at the bottom of a circular path based on the height of the path. However, there is confusion about the normal force increasing in a circular path and then decreasing once the path becomes straight. This is due to the fact that a centripetal force is required to keep the body moving in a circle, and as the skater descends, the centripetal force increases until the path levels out.

## Homework Statement

In my physics book (Young and Freedman 12 edition), in the chapter about conservation of energy, it teaches me that I can use the theory of conservation of energy and discover the velocity at the bottom of a circular path, having the height of this circular path. I understand and am ok with that part, however, there's another thing that I don't understand.

Suppose this image, if we calculate the velocity at the bottom, and then the net force, we will discover that the normal force is in fact applying 735 Newtons. Well, here's the thing, as soon as the circular paths ends and the "straight" path begins, the normal force will be simply equal to the weight again(245N), why does this happen? What I mean is, what in the circle magically makes the normal increase this much?

As you know, a body with no forces acting on it will move at a constant speed in a straight line. To make the skater complete the arc requires a centripetal force. As the skater descends he speeds up, so the centripetal force is greatest just before the arc levels out.

## What is circular motion?

Circular motion is the movement of an object along a circular path. It occurs when a force is applied perpendicular to an object's velocity, causing it to change direction and continuously move in a circular path.

## What is centripetal force?

Centripetal force is the force that acts on an object in circular motion, pulling it towards the center of the circle. It is necessary to keep the object moving in a circular path, as without it, the object would continue in a straight line.

## What is the relationship between circular motion and net force?

The net force in circular motion is always directed towards the center of the circle and is responsible for the object's continuous change in direction. This force is also equal to the product of the object's mass and its centripetal acceleration.

## How does the speed of an object in circular motion affect the net force?

The speed of an object in circular motion does not directly affect the net force. However, a change in speed will result in a change in the magnitude of the centripetal force required to keep the object in its circular path.

## Can an object in circular motion have a net force of zero?

Yes, an object in circular motion can have a net force of zero if its speed is constant and the centripetal force is equal to the object's centrifugal force (the force that acts in the opposite direction of the centripetal force). This results in the object maintaining a constant speed and direction in its circular path.