Calculate Distance for Work Done by Force

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Homework Help Overview

The discussion revolves around calculating the distance a rock was lifted given a force of 100 Newtons and a work done of 150 joules. The subject area is physics, specifically focusing on the relationship between force, work, and distance.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the equation W = FD and how to rearrange it to solve for distance. There are attempts to clarify the relationship between the variables and questions about unit consistency.

Discussion Status

Several participants have engaged in exploring the problem, with some providing hints and guidance on how to manipulate the equation. There is an ongoing examination of the correct units for the answer, and while some numerical values have been suggested, there is no explicit consensus on the final answer.

Contextual Notes

Participants note the importance of understanding the units involved in the calculations, as well as the guidelines against providing complete solutions. There is an emphasis on ensuring clarity in the reasoning process without arriving at a definitive conclusion.

Jajo
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w = Force times Distance
w = FD

4. A force of 100 Newtons was necessry to lift a rock. A total of 150 joules of work was done. How far was the rock lifted??

Please i really need to understand how to do this problem, if anyone reply's please try to give step by steps
 
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Jajo said:
w = Force times Distance
w = FD

4. A force of 100 Newtons was necessry to lift a rock. A total of 150 joules of work was done. How far was the rock lifted??

Please i really need to understand how to do this problem, if anyone reply's please try to give step by steps

Well, I'm not going to do it for you! You have an equation with three variables. You know two of them, and want to find the third. How do you think you should do this?
 
i tried forever but i can't find a way to do this...so i have the force (100N) and i have the Work (150Joules) so i how can i get the distance
 
Jajo said:
i tried forever but i can't find a way to do this...so i have the force (100N) and i have the Work (150Joules) so i how can i get the distance

You have the equation W=fd. Try rearranging this to make d the subject (i.e. to get d on its own). Can you do this?

[Hint: What does the equation look like if you divide both sides by f?]
 
so i would divide d to both sides so it would be w/d = f right?
 
Jajo said:
so i would divide d to both sides so it would be w/d = f right?
No; you want to find d.

Did you read this?
cristo said:
[Hint: What does the equation look like if you divide both sides by f?][/color]
 
so f = 1.5 meters or Newtons or joules
 
Jajo said:
so f = 1.5 meters or Newtons or joules

No. The number is correct, but which one of those units do you mean, they are not equivalent.
 
Ok i thought it was d...so the equation should look like this... W/F = D...so 150/100 = f...f = 1.5 meters or Newtons or Joules?
 
  • #10
Jajo said:
Ok i thought it was d...so the equation should look like this... W/F = D...so 150/100 = f...f = 1.5 meters or Newtons or Joules?

I made a mistake in my last post, you're correct in thinking it should be D, not f that is 1.5, but still it cannot be anyone of those units they are not equivalent. So which is it Newtons, meters or joules?
 
  • #11
"A force of 100 Newtons was necessry to lift a rock. A total of 150 joules of work was done. How far was the rock lifted??"

F=100N, right?
W=150J, right?

If W=FD, and you have F and W, but want to know D, set rearrange the equation to isolate the D.. W/F=D.. 100N/150J=1.5 meters.

Why 1.5 METERS? Well, Newtons is a metric unit, and Joules is a metric unit.. And the metric unit for distance is meter. Or.. you could expand the Newtons and joules..

Newton=kg*m/(s^2)
Joule=kg*(m^2)/(s^2)

Back to the problem.. [100*kg*m/(s^2)] / [150 kg*(m^2)/(s^2)]
That should result in 1.5, and all the units except meters cancel out, therefore, 1.5 meters.
 
  • #12
pugfug90 said:
"A force of 100 Newtons was necessry to lift a rock. A total of 150 joules of work was done. How far was the rock lifted??"

F=100N, right?
W=150J, right?

If W=FD, and you have F and W, but want to know D, set rearrange the equation to isolate the D.. W/F=D.. 100N/150J=1.5 meters.

Why 1.5 METERS? Well, Newtons is a metric unit, and Joules is a metric unit.. And the metric unit for distance is meter. Or.. you could expand the Newtons and joules..

Newton=kg*m/(s^2)
Joule=kg*(m^2)/(s^2)

Back to the problem.. [100*kg*m/(s^2)] / [150 kg*(m^2)/(s^2)]
That should result in 1.5, and all the units except meters cancel out, therefore, 1.5 meters.

Please don't provide complete solutions to homework problems.
 
  • #13
He and everyone else has pretty much solved it already, I'm just explaining "concepts" and "theory" so that he'll understand why the answer has to be in meters.
 
  • #14
pugfug90 said:
He and everyone else has pretty much solved it already, I'm just explaining "concepts" and "theory" so that he'll understand why the answer has to be in meters.

The OP had the correct numerical answer, however had not answered d_leet's question re the units. Besides, check out the PF guidelines: https://www.physicsforums.com/showthread.php?t=5374
guidelines said:
Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.
 

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