# Uniform Circular Motion - Finding Fc/Ft without mass

• Elatric
In summary, uniform circular motion is the constant motion of an object in a circular path at a fixed speed. This type of motion differs from others because of its specific path and constant speed. Centripetal force plays a crucial role in maintaining this motion by constantly changing the object's velocity direction. The formula for calculating centripetal force is Fc = (m*v^2)/r, and it is possible to find the force without knowing the mass of the object by rearranging the formula. However, the mass is an important factor in determining the strength of the force.
Elatric

## Homework Statement

A boy ties a rock to a 0.95 m string and swings it in a horizontal circle directly over his head so that it completes one revolution every 0.75 s. What is the tension in the string?
So we know r and we can calculate V, but that's all I can deduce

Fc=(mv^2)/r
V=(2*pi*r)/t

## The Attempt at a Solution

2*pi*.95/.75= 7.9587 m/s
That's how far I got. I know the masses cancel with ma=mv^2/r but then I end up finding the acceleration. Help?

I think you need m.

## 1. What is uniform circular motion?

Uniform circular motion is the motion of an object in a circular path at a constant speed. This means that the object travels a fixed distance in a fixed amount of time, resulting in a uniform or constant speed.

## 2. How is uniform circular motion different from other types of motion?

Uniform circular motion is different from other types of motion because it follows a specific path, the circular path, and has a constant speed. Other types of motion, such as linear motion, do not follow a specific path and may have varying speeds.

## 3. What is the role of centripetal force in uniform circular motion?

Centripetal force is the force that keeps an object moving in a circular path. In uniform circular motion, it is responsible for constantly changing the direction of the object's velocity, which allows it to maintain its circular path.

## 4. How do you calculate the centripetal force in uniform circular motion?

The formula for calculating the centripetal force in uniform circular motion is Fc = (m*v^2)/r, where Fc is the centripetal force, m is the mass of the object, v is the velocity, and r is the radius of the circular path.

## 5. Can you find the centripetal force without knowing the mass of the object?

Yes, it is possible to calculate the centripetal force without knowing the mass of the object. This can be done by rearranging the formula to solve for mass: m = (Fc*r)/v^2. However, it is important to note that the mass is a key factor in determining the strength of the force, so it is ideal to have this information when calculating the centripetal force.

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