Help with Rotation Freq of 10kg Ball on 5m String

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In summary, rotation frequency refers to the number of rotations an object makes per unit of time and is typically measured in RPM or RPS. It can be calculated by dividing the number of rotations by the time it takes to complete them, and is inversely proportional to the time. The mass of an object does not directly affect its rotation frequency, but the distribution of mass and length of the string can. Other factors that can affect rotation frequency include string length, tension, mass and distribution, and external forces.
  • #1
tut_einstein
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A ball with mass m = 10kg is attached to one end of a massless string of length r = 5m.?
The other end of the string is fixed about a point. The ball rotates about this point at a frequency of 1 Hz/ While the ball is rotating, the string is reeled in until its length r = 3m. If the system is not otherwise disrupted in any way, what is the new frequency of rotation?
25/9 Hz
5/3 Hz
1 Hz
3/5 Hz
9/25 Hz

can you help out this hard and I've tried everything? Please


:smile:
 
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What have you tried?
 
  • #3
Sure, I'd be happy to help! Let's start by looking at the formula for frequency of rotation, which is f = (1/2π) * √(g/r). Here, g represents the gravitational acceleration, which we can assume to be 9.8 m/s^2. We also know that the mass of the ball is 10kg and the original length of the string is 5m. So, plugging in these values, we get the original frequency of rotation to be 1 Hz.

Now, let's consider the new length of the string, which is 3m. Plugging this value into the formula, we get the new frequency of rotation to be f = (1/2π) * √(9.8/3) = 5/3 Hz. So, the correct answer is option 5/3 Hz.

I hope this helps! Let me know if you have any further questions.
 

What is rotation frequency?

Rotation frequency refers to the number of rotations or revolutions a object makes per unit of time. It is typically measured in rotations per minute (RPM) or rotations per second (RPS).

How do you calculate the rotation frequency?

The rotation frequency can be calculated by dividing the number of rotations by the time it takes to complete those rotations. For example, if a ball completes 10 rotations in 1 minute, the rotation frequency would be 10 RPM (10 rotations / 1 minute = 10 RPM).

What is the formula for calculating rotation frequency?

The formula for calculating rotation frequency is: rotation frequency = number of rotations / time. This means that the rotation frequency is inversely proportional to the time it takes to complete the rotations.

How does the mass of the object affect its rotation frequency?

The mass of an object does not directly affect its rotation frequency. However, the distribution of mass and the length of the string can impact the rotation frequency. A heavier object with a longer string may have a lower rotation frequency compared to a lighter object with a shorter string.

What factors can affect the rotation frequency of an object on a string?

Some factors that can affect the rotation frequency of an object on a string include the length of the string, the tension in the string, the mass and distribution of mass of the object, and any external forces acting on the object (such as air resistance).

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