Radius and centripetal relation

In summary, the conversation discusses the use of the equation F=mv^2/r to solve a problem involving centripetal force. The questioner is confused about why the acceleration is written as 2a instead of 2/a, and the responder explains that the radius and speed both change in the problem, and there is a simpler expression for the acceleration using angular velocity. The questioner then realizes their mistake and clarifies their understanding.
  • #1
SUSUSUSUSUSUSUSU

Homework Statement


the file given

Homework Equations



F=mv^2/r

The Attempt at a Solution


I do not understand why the centripetal force is 2a and not 2/a since the radius of X is twice longer.

When I use the equation above, raidius is inversely proportional to the acceleration.

Is radius proportional to the accerlation? Then why it is?[/B]


 

Attachments

  • 스크린샷 2017-10-30 13.48.53.png
    스크린샷 2017-10-30 13.48.53.png
    17.2 KB · Views: 471
Physics news on Phys.org
  • #2
Both speed and radius change. And I don't see how you would place the a in the denominator. That doesn't even give an acceleration in terms of units.
The angular velocity is constant. There is an expression for the acceleration that uses the angular velocity, that makes the problem easier.
 
  • #3
so
mfb said:
Both speed and radius change. And I don't see how you would place the a in the denominator. That doesn't even give an acceleration in terms of units.
The angular velocity is constant. There is an expression for the acceleration that uses the angular velocity, that makes the problem easier.
sorry i got a/2 hahah
 
  • #4
SUSUSUSUSUSUSUSU said:
so

sorry i got a/2 hahah

when i use 2R, the equation will be mv^2/2R which is a/2. this is what i have got
 
  • #5
The speed changes as well, don’t forget that.
 

Related to Radius and centripetal relation

1. What is the definition of radius?

The radius is a measurement of the distance from the center of a circle to its edge. It is often denoted by the letter "r" and is a key component in calculating the circumference, area, and other properties of a circle.

2. How is the radius related to the circumference of a circle?

The radius and the circumference of a circle are directly related. In fact, the circumference is equal to 2π (pi) times the radius. This means that if you know the radius of a circle, you can easily calculate its circumference by multiplying the radius by 2π.

3. What is the difference between radius and diameter?

The diameter of a circle is the distance across the circle passing through its center, whereas the radius is the distance from the center to the edge. The diameter is always twice the length of the radius, or d = 2r.

4. How is centripetal force related to the radius of a circle?

Centripetal force is the force that keeps an object moving in a circular path. It is directed towards the center of the circle and its magnitude is dependent on the mass of the object, its velocity, and the radius of the circle. The greater the radius, the less centripetal force is required to keep the object moving in a circular path.

5. What is the formula for calculating the radius of a circle?

The formula for calculating the radius of a circle is r = c/2π, where c is the circumference of the circle. You can also use the formula r = √(A/π), where A is the area of the circle. These formulas can be rearranged to solve for the circumference or area, depending on which value is known.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
392
  • Introductory Physics Homework Help
Replies
8
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
709
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
2K
Back
Top