Mistake in Dynamics Circular Problem's Solution

In summary, the conversation involved discussing a problem involving the calculation of length of string and force. The speaker initially had trouble understanding the solutions and had calculated the radius and force with only 2 significant figures. However, after realizing the mistake, they corrected their calculations to include 3 significant figures and found that their answers were correct. The conversation ended with confirming that the reported radius was incorrect, most likely due to a mistype.
  • #1
alingy1
325
0
Please look at pictures.
I do not understand the solutions;

Here is how I find length of string:
5m/s*1.2s/rev=6m/rev=circumference=2piR
R=0.95m.


For the force:
T=mv^2/r= 0.350 kg *5^2/0.95= 9.21N They got 9.16N?
 

Attachments

  • Screen Shot 2014-05-22 at 5.29.11 PM.png
    Screen Shot 2014-05-22 at 5.29.11 PM.png
    2.7 KB · Views: 415
  • Screen Shot 2014-05-22 at 5.29.06 PM.png
    Screen Shot 2014-05-22 at 5.29.06 PM.png
    10.3 KB · Views: 442
Physics news on Phys.org
  • #2
The numbers in the problem are stated to 3 significant figures. So, make sure you keep at least 3 significant figures in your intermediate calculations. What do you get for R to 3 significant figures?
 
  • #3
Well the answer I got is 0.95m which is almost twice as big as the radius they found.
I keep all my sig figs on my calculator.
 
  • #4
I don't know what is going on! :O
 
  • #5
You got R = .95 m. That has only 2 significant figures. What do you get to 3 significant figures?

When you calculated T, it looks like you used r = .95 m. Again, only 2 significant figures for r. What do you get for T if you use a value for r that is accurate to 3 significant figures?
 
  • #6
OK, I did not see the answer they had for R. Their answer is wrong, yours is right. But you should give it to 3 significant figures.
 
  • Like
Likes 1 person
  • #7
R=0.955m.
T=9.16N. You were right! Ok. This was my bad.
What about the radius? The radius they report is definitely wrong?
 
  • #8
Perfect! Everything works out great!
 
  • #9
Good!
 
  • #10
their radius is mistyped- probably 4 was meant to be a 9...
as for the rest, follow TSny's post
 

What is a mistake in dynamics circular problem's solution?

A mistake in dynamics circular problem's solution refers to an error or inaccuracy in the mathematical calculations or reasoning used to solve a problem related to circular motion. This can lead to an incorrect solution and may impact the accuracy of any conclusions drawn from the problem.

How common are mistakes in dynamics circular problem's solutions?

Mistakes in dynamics circular problem's solutions are not uncommon, especially for those who are new to the subject or have limited experience with circular motion problems. It is important to carefully check and double-check any calculations and assumptions made in order to avoid these mistakes.

What are some common mistakes made in dynamics circular problem's solutions?

Some common mistakes made in dynamics circular problem's solutions include using incorrect formulas or equations, failing to properly account for all forces acting on an object, and making incorrect assumptions about the motion of the object. It is important to carefully review the problem and all relevant concepts before attempting to solve it.

How can I avoid making mistakes in dynamics circular problem's solutions?

To avoid making mistakes in dynamics circular problem's solutions, it is important to have a thorough understanding of the concepts and formulas involved in circular motion. It is also helpful to carefully read and analyze the problem and make a plan for solving it before attempting any calculations. Additionally, double-checking all calculations and assumptions can help catch any potential mistakes.

What should I do if I discover a mistake in my dynamics circular problem's solution?

If you discover a mistake in your dynamics circular problem's solution, it is important to carefully review your work and identify where the mistake was made. Once you have identified the error, you can correct it and rework the problem to arrive at the correct solution. It may also be helpful to seek assistance from a teacher or tutor to better understand where the mistake was made and how to avoid it in the future.

Similar threads

  • Introductory Physics Homework Help
2
Replies
35
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
27
Views
3K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
931
  • Introductory Physics Homework Help
Replies
7
Views
4K
Back
Top