How does centripetal force affects the path?

In summary, when a charged particle moves in a magnetic field, the force acting on it is always perpendicular to its velocity. This results in a constant acceleration and a circular path, rather than a spiral path that gets closer to the center. The possibility of different paths arises when the force varies with time, but in this case, the force remains constant, resulting in a perfect circle. This can be understood by considering the paths of a car with constant speed and different steering inputs.
  • #1
jaobyccdee
33
0
When there's magnetic field, a charged particle moves in a circle. I would like to ask why won't the circle goes smaller even when there's a force pointing inward (towards the center of the circle). Thank you!
 
Physics news on Phys.org
  • #2
Any force that acts perpendicularly to the direction of motion doesn't change a particle's speed, only the direction. And the magnetic force always acts perpendicularly to the direction of motion.
 
  • #3
So when it changes the direction of the path, why will it become a perfect circle instead of a path that circles around closer and closer to the center? Sorry i don't know the word to describe that path...
 
  • #4
jaobyccdee said:
So when it changes the direction of the path, why will it become a perfect circle instead of a path that circles around closer and closer to the center?
The word you're looking for is spiral. The reason the path is a circle in this case is because the force (and acceleration) are constant as well as perpendicular to the path (velocity). If the amount of force varies with time, then just about any path would be possible, with the only constraint that speed is constant. The force could be adjusted to create a spiral, an ellipse, a parabola, a hyperbola, a sine wave, ... , any path that is possible with constant speed and only direction changes. For example, think of the possible paths your car could follow while moving at constant speed with just steering inputs, however if you hold the steering wheel in one position, then the car's path will be a circle (or a straight line) (assuming it doesn't slide).
 
Last edited:
  • #5
Thank you:)
 

1. How does the centripetal force affect the path of an object?

The centripetal force is responsible for causing an object to move in a circular path. It acts perpendicular to the direction of motion, towards the center of the circle. Without this force, the object would continue in a straight line.

2. What determines the strength of the centripetal force?

The strength of the centripetal force is determined by the mass of the object, its velocity, and the radius of the circular path. The greater the mass and velocity, or the smaller the radius, the stronger the centripetal force will be.

3. How is centripetal force different from centrifugal force?

Centripetal force is a real force that acts on an object to keep it moving in a circular path. Centrifugal force is often referred to as a "fictitious" force, as it is a perceived force that appears to push an object away from the center of the circle, but is actually an effect of the object's inertia.

4. Can centripetal force change the speed of an object?

Yes, centripetal force can change the speed of an object by altering its direction of motion. As the object moves in a circular path, the direction of its velocity is constantly changing, which means its speed also changes. This is why objects moving in a circular path have a constant acceleration.

5. How does centripetal force affect different types of motion?

Centripetal force can affect any type of motion that involves a circular path. This includes objects moving in a horizontal circle, such as a car on a curve, as well as objects moving in a vertical circle, such as a rollercoaster. The force acts in the same direction, towards the center of the circle, regardless of the type of motion.

Similar threads

Replies
21
Views
1K
Replies
15
Views
2K
Replies
6
Views
840
Replies
16
Views
1K
Replies
24
Views
1K
  • Mechanics
Replies
6
Views
2K
Replies
7
Views
1K
  • Mechanics
Replies
6
Views
1K
Back
Top