Calculating Centripetal Force for 6 kg Object

• John78
In summary: You correctly applied the formula for centripetal force (CF = mv^2/r) and calculated the circumference (C = 2*pi*r) to use in the formula. Your final answer of 51112 is in the correct units of Newtons (N).
John78

Homework Statement

Find the centripetal force required to rotate 6 kg object in a circle at a radius of 6m at one revolution per second.

Homework Equations

C.F. = mv2/r

3. The Attempt at a Solution [/b

Circumference=2 pi r=2*3.14*6=37.68

C.F. = 6*(37.68)2/6=1419.78

I just want to check whether my working is correct or not.

that's about what I got too ^^

Looks like you wrote down
CF = m v2/r

but then you calculated the circumference, C = 2 π r

and then you said,

CF = r C2/6 = C2

Why would you expect the centripetal force to be equal to the square of the circumference?

It really is not.

Try it again, starting with CF = m r ω2 and see how that turns out for you. You failed to get the time information into the problem.

so

CF = m r ω2

CF = 6*6*(37.68)2=51112?

OldEngr63 said:
Looks like you wrote down
CF = m v2/r

but then you calculated the circumference, C = 2 π r

and then you said,

CF = r C2/6 = C2

Why would you expect the centripetal force to be equal to the square of the circumference?

It really is not.

Try it again, starting with CF = m r ω2 and see how that turns out for you. You failed to get the time information into the problem.

That's not really what he is doing, I think... He is doing CF = m v^2 / r, it just so happens that v is one circumference per second and that m and r have the same numerical value...

now i am confused :C

John78 said:
now i am confused :C

You shouldn't be, you got it right the first time around.
However, to get it right with the second formula, you have to use the proper value for ω, which in this case is 2π/s.

It would probably clear things up, if you would carry the units throughout your calculation and not just the numbers, that way you can always check if your result makes sense.

I think your working is correct

1. How do you calculate centripetal force for a 6 kg object?

To calculate centripetal force for a 6 kg object, you will need to know the mass of the object, the velocity at which it is moving, and the radius of the circular path it is following. The formula for calculating centripetal force is F = (m*v^2) / r, where F is the centripetal force, m is the mass, v is the velocity, and r is the radius.

2. What units are used to measure centripetal force?

Centripetal force is typically measured in units of newtons (N), which is the standard unit for force in the International System of Units (SI). However, other units such as pounds (lbs) or dynes (dyne) may also be used to measure centripetal force.

3. Can centripetal force be negative?

No, centripetal force cannot be negative. Since it is a force that is directed towards the center of a circular path, it is always positive. If the direction of the force changes, it is simply referred to as a different type of force, such as centrifugal force.

4. How does the mass of the object affect the centripetal force?

The mass of an object has a direct relationship with the centripetal force. As the mass of the object increases, the centripetal force required to keep it in a circular path also increases. This means that a heavier object will require a stronger force to maintain its circular motion compared to a lighter object.

5. What happens to the centripetal force if the velocity increases?

If the velocity of an object increases, the centripetal force required to keep it in a circular path will also increase. This is because the force needed to overcome the object's inertia and maintain its motion in a curve is directly proportional to its speed. Therefore, a faster-moving object will require a greater centripetal force to keep it in a circular path.

Replies
28
Views
2K
Replies
5
Views
3K
Replies
17
Views
2K
Replies
17
Views
1K
Replies
2
Views
925
Replies
3
Views
1K
Replies
7
Views
3K
Replies
1
Views
2K
Replies
8
Views
2K
Replies
1
Views
1K