Is this a mistake on the answer key? (Newton's Laws)

In summary, the conversation discusses the angle measurement of 60 degrees and 30 degrees in relation to the y-axis and x-axis. It also mentions the use of these angles in solving a physics problem. There is some confusion initially, but it is clarified that the 30 degree angle is in the correct place and the vertical and horizontal components of the force can be calculated using trigonometric functions. The conversation ends with gratitude for the help provided.
  • #1
Lori

Homework Statement



upload_2017-11-5_18-2-21.png

Homework Equations



F = ma
[/B]

The Attempt at a Solution



Why is the angle 60 degrees? Isn't it 30 degrees? [/B]
 

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  • #2
Lori said:
Why is the angle 60 degrees? Isn't it 30 degrees?
Because the angle is being measured from the y-axis rather than the x-axis. The angle to the x-axis is ##30^{\circ}## and the angle to the y-axis is ##60^{\circ}##.
 
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  • #3
Ahhhh nevermind, i think they used the 30 degrees as the angle of the force from top left... Man. these problems are very unclear .
 
  • #4
Lori said:
i think they used the 30 degrees as the angle of the force from top left... Man. these problems are very unclear .

No it's clear. The 30 degree angle on the drawing is in the correct place. P is at 30 degrees to the horizontal axis.

The vertical component of P is PCos60 or PSin30 as these are same thing.

The horizontal component of P is PSin60 or PCos30 as these are the same thing.
 

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  • #5
Sorry if that was confusing, I agree with your solution.
 
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  • #6
CWatters said:
Sorry if that was confusing, I agree with your solution.
No it's fine! Thanks for helping me out. I'm trying to prepare for my physics exam as much as I can! I think I really learned a lot from you guys :)
 

1. What should I do if I think there is a mistake on the answer key for Newton's Laws?

If you believe there is a mistake on the answer key, the first thing you should do is double check your own work to ensure that you have not made a mistake. If you are still confident that the answer key is incorrect, you should consult with your instructor or a classmate to get a second opinion. It is also helpful to provide specific details on why you believe there is a mistake, such as a discrepancy in calculations or a contradiction with another reliable source.

2. How common are mistakes on answer keys for Newton's Laws?

In general, there are bound to be some mistakes on answer keys for any subject, including Newton's Laws. However, the frequency of mistakes may vary depending on the source of the answer key. It is important to remember that answer keys are created by humans and are not always perfect, so it is always a good idea to double check your work and consult with others if you have any doubts.

3. Is it possible for there to be multiple correct answers for a question on Newton's Laws?

Yes, it is possible for there to be multiple correct answers for a question on Newton's Laws. This is because Newton's Laws are principles that describe the relationship between forces and motion, and there are often multiple ways to apply these principles to a given problem. If you are unsure about which answer is correct, it is best to consult with your instructor or a classmate for clarification.

4. How can I avoid making mistakes when answering questions about Newton's Laws?

The best way to avoid making mistakes when answering questions about Newton's Laws is to thoroughly understand the principles and practice solving problems using them. It is also helpful to double check your work and consult with others if you are unsure about an answer. Additionally, reading and following the directions carefully can also help prevent mistakes.

5. What should I do if I find a mistake on the answer key after the assignment has been graded?

If you discover a mistake on the answer key after the assignment has been graded, you should bring it to the attention of your instructor. They will then review the mistake and determine if it has affected your grade. If it has, they may adjust your grade accordingly. However, it is important to note that it is ultimately at the instructor's discretion whether or not to make any changes to your grade.

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