Solving RPM Problems: Understanding Maximum Speed and Revolutions

  • Thread starter Thread starter sybozo
  • Start date Start date
  • Tags Tags
    Rpm
AI Thread Summary
To find the maximum RPM speed when 4,180 RPM is 38%, divide 4,180 by 0.38, resulting in a maximum speed of approximately 11,000 RPM. For the second question regarding revolutions in 30 seconds at 100 RPM, the gear completes 100 revolutions per minute, so in 30 seconds, it would complete 50 revolutions. The confusion arises from the relationship between time for one revolution and total time, emphasizing that T refers to the time for a single revolution, not the total time given. The discussions highlight the need for clarity in understanding RPM as a frequency measure and the conversion between time and revolutions. Overall, the thread illustrates common misunderstandings in solving RPM-related problems.
sybozo
Messages
4
Reaction score
0

Homework Statement



Q1) If 4,180rpm is 38% of the max rpm speed what is the max rpm speed?

Q2)Determine the number of revolutions a gear completes in 30 seconds when
the gear turns at 100 revolutions per min

2. The attempt at a solution

Q1) Alright for this part, I was pretty confuse when they asked for the max rpm speed and the given percentage. Do I have to convert the percentage to a decimal and then convert it to rads? What do they also mean by the maxrpm speed?
If I'm not mistaken, rpm is a measure of frequency right? Does that mean f=4,180rpm? In other words do I just put it in the frequency formula or should I divide it by 2∏ then put it in the frequency formula? ω=2∏f But then again it can't be ω because they're asking for speed not velocity. I could use f=1/T but they didn't give me the time. ARGH! I'm so confused!

Q2)Alright 1 revolution is equal to 60s or 2∏ right? (correct me if I'm wrong). So by using this formula, f=1/T making T=30s and well now I'm stuck

Note:Q1 and Q2 are different problems/questions
 
Physics news on Phys.org
1) if 4180 = 38%, what is equal to 100%?

2) T is not 30s, T is the time it takes for the gear to complete 1 rev.
 
Xisune said:
1) if 4180 = 38%, what is equal to 100%?

4180 = 38%
110 = 1%
11000 = 100%?

Would that be correct?

Xisune said:
2) T is not 30s, T is the time it takes for the gear to complete 1 rev.

Alright so 1 rev is = 2∏ right? So, well, not sure what to do after that. I'm completely lost. Sorry about that :frown:

Does the 2∏ have to be divided by 100 or something?
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top