Question involving LAWS OF WORK

  • Thread starter demode
  • Start date
  • Tags
    Laws Work
In summary: I truly appreciate it.In summary, using a set of pulleys, a mover is able to raise a 1000-N crate a distance of 5.00 m by pulling in 20.0 m of cord. To determine the effort required for an ideal machine, the equation 1000N * 5.0 M = XN * 20.0 M can be used, resulting in an effort of 250 N. However, if the actual applied effort is 300 N, the extra 50 N is used to overcome friction. The work output is calculated by multiplying the given force of 1000 N by the distance of 5.0 m, resulting in 5000 J.
  • #1
demode
30
0
I have been given the prompt:

"Using a set of pulleys, a mover raises a 1000-N crate a distance of 5.00 m. This is accomplished by pulling in 20.0 m of cord"

I need to find

  • How much effort would have to be applied if this were an ideal machine
  • If the effort actually applied is 300 N, what force is used to overcome friction?
  • What is the work output?
  • What is the work input?
  • What is the real mechanical advantage?

I don't know if I have done this correctly so if someone would be willing to verify my answers or guide me through this, it would be appreciated.


1. In an ideal machine, I believe work input is equal to work output. With that being said, I can set up the equation 1000N * 5.0 M = XN * 20.0 M, then I can solve X for 250 N... Correct?

2. I'm not too sure what it means when it asks to OVERCOME friction, so what do i do?

3. Work output is just equal to force * distance, so we evaluate the given 1000N force times the given 5.0 M distance and get 5000 J, Correct?

4. Work input is just equal to force * distance as well, so we evaluate the value we solved for in number 1 (250) and multiply by the given 25 m distance and get 5000J, correct?

5. Not sure at all what to do :confused:
 
Physics news on Phys.org
  • #2
demode said:
I have been given the prompt:

"Using a set of pulleys, a mover raises a 1000-N crate a distance of 5.00 m. This is accomplished by pulling in 20.0 m of cord"

I need to find

  • How much effort would have to be applied if this were an ideal machine
  • If the effort actually applied is 300 N, what force is used to overcome friction?
  • What is the work output?
  • What is the work input?
  • What is the real mechanical advantage?

I don't know if I have done this correctly so if someone would be willing to verify my answers or guide me through this, it would be appreciated.


1. In an ideal machine, I believe work input is equal to work output. With that being said, I can set up the equation 1000N * 5.0 M = XN * 20.0 M, then I can solve X for 250 N... Correct?yes
2. I'm not too sure what it means when it asks to OVERCOME friction, so what do i do?Idealy it would take 250N of force, but it took 300N. So why was the extra 50N required?

3. Work output is just equal to force * distance, so we evaluate the given 1000N force times the given 5.0 M distance and get 5000 J, Correct?yes

4. Work input is just equal to force * distance as well, so we evaluate the value we solved for in number 1 (250) the problem wants you to use 300N here, not the ideal 250N and multiply by the given 25 m you mean 20mdistance and get 5000J, correct?that works out to 6000J

5. Not sure at all what to do :confused:
5. Ideal MA is 4, since it took just 1/4 of the weight to move it (250/1000 =1/4). So its actual MA is??
 
  • #3
alright man, I understand it. Thanks SO much
 

Related to Question involving LAWS OF WORK

1. What is the definition of "Laws of Work"?

The Laws of Work, also known as the laws of thermodynamics, are a set of physical laws that govern the behavior and interactions of energy and matter. These laws explain how energy is transferred and transformed, and how it affects the behavior of systems.

2. What are the three laws of thermodynamics?

The first law states that energy cannot be created or destroyed, only transferred or converted from one form to another. The second law states that the total entropy of a closed system will always increase over time. The third law states that it is impossible to reach absolute zero temperature through a finite number of steps.

3. How do the laws of work apply to everyday life?

The laws of work apply to everyday life in many ways. For example, they explain why a cup of hot coffee will eventually cool down, why it is impossible to create a perpetual motion machine, and why our bodies require energy to function. These laws are also used in many industries, such as engineering and environmental science, to design and improve systems and processes.

4. What is the role of energy in the laws of work?

Energy is a fundamental component of the laws of work. It is what allows for the transfer and transformation of matter and is essential for the functioning of all systems. The laws of work help us understand how energy is transferred and transformed, and how it affects the behavior of matter and systems.

5. Are the laws of work ever violated?

The laws of work are considered to be fundamental laws of the universe and have been extensively tested and observed in various situations. While they are not typically violated, there are some exceptions at the quantum level, such as the uncertainty principle. However, these exceptions do not invalidate the laws, but rather demonstrate the complexity and nuances of the physical world.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
996
  • Introductory Physics Homework Help
Replies
5
Views
803
  • Introductory Physics Homework Help
Replies
18
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
1K
Replies
1
Views
745
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
2
Replies
56
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
873
  • Introductory Physics Homework Help
Replies
2
Views
927
Back
Top