What is the correct way to find the speed of the bucket in circular motion?

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Homework Help Overview

The discussion revolves around a physics problem involving circular motion, specifically focusing on determining the speed of a bucket being whirled in a vertical circle. The scenario includes parameters such as mass, radius, and tension in the rope.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants are exploring the relationship between centripetal acceleration and speed, with some attempting to derive speed from given acceleration values. There is also a focus on clarifying the definitions and relationships in circular motion.

Discussion Status

The discussion is ongoing, with participants questioning the correctness of calculations and interpretations. Some guidance has been offered regarding the relationship between acceleration and speed, but there is no explicit consensus on the correct approach or final answer.

Contextual Notes

Participants are grappling with the definitions of acceleration and speed in the context of circular motion, and there is an acknowledgment of missing information, such as the time for one complete rotation.

RedBurns
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bucket of mass 1.80 kg is whirled in a vertical circle of radius 1.10 m. At the lowest point of its motion the tension in the rope supporting the bucket is 25.0 N.
Find the speed of the bucket.

f(t)-mg=mA

25-17.64=1.8 A
7.36 = 1. 8 A
A= 4.08

I'm told the answer above is incorrect, and someone point out my mistake?
 
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RedBurns said:
bucket of mass 1.80 kg is whirled in a vertical circle of radius 1.10 m. At the lowest point of its motion the tension in the rope supporting the bucket is 25.0 N.
Find the speed of the bucket.

f(t)-mg=mA

25-17.64=1.8 A
7.36 = 1. 8 A
A= 4.08

I'm told the answer above is incorrect, and someone point out my mistake?

They are asking for the speed . You found the centripetal *acceleration*. You know how the two are related in circular motion?
 
acceleration is velocity squared over time

Speed would be 2 pi radius over time

4.08= v^2/1.10
4.08/1.1 = 3.71
Square root of 3.71 = 1.93

Would 1.93 then be the speed?
 
RedBurns said:
acceleration is velocity squared over time
no! (over the radius! Not the time!)

Speed would be 2 pi radius over time
I don't see how this help syou since you don't have the time...But it's true, if by "time" you mean the time for one rotation, the period.

4.08= v^2/1.10
4.08/1.1 = 3.71
Square root of 3.71 = 1.93

Would 1.93 then be the speed?

Check you algebra!
 

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