How Far Will the Cart Travel at Increased Speeds?

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Homework Help Overview

The discussion revolves around a physics problem involving a cart's motion on a track. Initially, the cart moves at 0.5 m/s and comes to rest after traveling 1 m. The problem is then repeated with the cart starting at 1 m/s, and participants are tasked with determining how far the cart travels before stopping.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore the relationship between initial velocity and stopping distance, with some suggesting that displacement is proportional to the square of the velocity. Others question the assumption that time is the same in both scenarios and discuss the implications of applied force on displacement.

Discussion Status

The conversation is ongoing, with various interpretations of the problem being explored. Some participants have provided reasoning for their answers, while others express confusion about the calculations and assumptions made. There is no clear consensus, as differing views on the physics principles involved are being debated.

Contextual Notes

Participants mention the same track being used for both trials and discuss the implications of this on the problem. There is also mention of an answer key that may not align with the reasoning presented in the thread.

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Homework Statement


A cart is initially moving at 0.5 m/s along a track. The cart comes to rest after traveling 1 m. The experiment is repeated on the same track, but now the cart is initially moving at 1 m/s. How far does the cart travel before coming to rest.[/B]

Homework Equations


W=ΔKE[/B]
Ffd=1/2mv^2
d is proportional to velocity squared

The Attempt at a Solution



0.5^2=0.25
1^2=1
1/0.25=4m

The answer is 2 meters
 
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what is problem there. Do you know the exact answer. I may try. But it is not as complex as you think. it is basic. The cart displacement depends on applied force.
 
I already posted the problem and my attempt at the solution. But I got the wrong answer.
 
yes i got the answer
 
It is not the energy problem
 
it is kinematics problem. Look there is only matter time. Ok
 
Explain..?
 
time is equal both cases. so time is 2s
 
That doesn't really help..?
 
  • #10
Ok, of course, you need to know the basic physics. v=x/t...0.5=1/t...t=2s... for second case...x=vt----------v=1*2=2m
 
  • #11
Ahmad Hossain said:
what is problem there. Do you know the exact answer. I may try. But it is not as complex as you think. it is basic. The cart displacement depends on applied force.

Ahmad Hossain said:
time is equal both cases. so time is 2s

Ahmad Hossain said:
Ok, of course, you need to know the basic physics. v=x/t...0.5=1/t...t=2s... for second case...x=vt----------v=1*2=2m

I do not believe you can just assume the times are the same.
 
  • #12
you may forget, you use the same track...so common sense.
 
  • #13
it is not so complex. Read the book...it is better
 
  • #14
Ahmad Hossain said:
you may forget, you use the same track...so common sense.

That doesn't make sense at all... Thats like saying any two trains on the same track will stop in the same amount of time. You are completely ignoring other factors.
 
  • #15
that's why i advice you read the book Tipler physics...it is very high level book...so you can find the answer. In forum i cannot explain all things in a short time ...i am also busy,,,,,,,,,I just give you the right answer...your conception you need to clear it...I cannot do it in a short time...may be you do not have deep knowledge in physics.so it can happen.
 
  • #16
Ahmad Hossain said:
that why i advice you read the book Tipler physics...it is very high level book...so you can find the answer. In forum i cannot explain all things in a short time ...i am also busy,,,,,,,,,I just give you the right answer...your conception you need to clear it...I cannot do it in a short time...may be you do not have deep knowledge in physics.so it can happen.

I think it is best you let someone else help on this one. You are only telling me I do not understand physics instead of solving the question correctly. I already provided you the answer and then you just told me my answer again.
 
  • #17
Scholar1 said:
0.5^2=0.25
1^2=1
1/0.25=4m

The answer is 2 meters
Why do you think the answer is 2 meters?

I'd say that your initial answer of 4 m was correct.
 
  • #18
Doc Al said:
Why do you think the answer is 2 meters?

Thanks for your reply. I actually thought the answer was 4m based on my work above. The answer key says the answer is 2m. Therefore I clearly am doing something wrong and need help. Hence I posted on this forum...
 
  • #19
Scholar1 said:
The answer key says the answer is 2m. Therefore I clearly am doing something wrong and need help.
Not necessarily. The answer key can be wrong.

The key is: what is the same between the two trails? The assumption must be that the retarding force and thus the acceleration is the same.

Which leads to your answer of 4 m. The faster car has 4 times the energy and thus 4 times the work must be done to stop it and thus 4 times the distance.
 
  • #20
So you are saying I am correct?
 
  • #21
Ahmad Hossain said:
time is equal both cases. so time is 2s
Why in the world would you think the time was the same? And where did you get 2 s?
 
  • #22
Scholar1 said:
So you are saying I am correct?
Yes.
 
  • #23
Doc Al said:
Not necessarily. The answer key can be wrong.

The key is: what is the same between the two trails? The assumption must be that the retarding force and thus the acceleration is the same.

Which leads to your answer of 4 m. The faster car has 4 times the energy and thus 4 times the work must be done to stop it and thus 4 times the distance.

Doc Al said:
Yes.
Wonderful. Ahmad Hossain just trolled me for an hour and insulted me for no reason.
 
  • #24
Scholar1 said:
I think it is best you let someone else help on this one. You are only telling me I do not understand physics instead of solving the question correctly. I already provided you the answer and then you just told me my answer again.
Doc Al said:
Yes.
no, 4m is totally incorrect...because common sense
 
  • #25
Ahmad Hossain said:
no, 4m is totally incorrect...because common sense
Please state your reasoning and calculation. "Common sense" is not a physics principle.
 
  • #26
Ahmad Hossain said:
no, 4m is totally incorrect...because common sense

I do not think you understand physics and merely are a troll.
 
  • #27
just you should go to you professor ask that I am wrong or he is wrong...I know something but it is not mean I know false.
 
  • #28
Doc Al said:
Please state your reasoning and calculation. "Common sense" is not a physics principle.
you told me why 4m...
 
  • #29
Ahmad Hossain said:
just you should go to you professor ask that I am wrong or he is wrong...I know something but it is not mean I know false.
We already know that you are wrong. Unless you show us your calculations to prove otherwise.
 
  • #30
Ahmad Hossain said:
you told me why 4m...
I did and so did Scholar1. Show us where the mistake lies.
 

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