Calculating Force and Power in Elevator Systems- Step by Step Guide

  • Thread starter KraYzie
  • Start date
In summary: For #2, the elevator car's mass is 1.20x10^3 kg and it is designed to carry a maximum load of 9.5x10^2 kg. So, the power that the motor must deliver to raise the car at a speed of 2.5 m/s is 9.0x10^19 N.
  • #1
KraYzie
6
0
How do you do these problems:

1) What is the magnitude of the force required to accelerate an electron of mass 9.1x10^-31 kg from rest to a speed of 2.0x10^7 m/s for a distance of 0.5 cm

(a) 1.8 x 10^-21 N
(b) 9.0 x 10^-19 N
(c) 1.8 x 10^-16 N
(d) 3.6 x 10^-14 N

2) In an elevator system, a motor rotates a shaft wrapping or unwrapping a chain that raises or lowers the elevator car. The car's mass is 1.20x10^3 kg and is designed to carry a maximum load of 9.5x10^2 kg. While in motion, a constant frictional force of 3.5x10^4 N acts on the car.

(a) What power must the motor deliver to raise the fully loaded car at a speed of 2.5 m/s?

(b) The elevator system is modified by connecting a free-hanging 5.0x10^2 kg counterweight to the chain that passes over the shaft of the motor, as shown below. What power must the motor now deliver to raise the fully loaded car at a speed of 2.5 m/s?

Thank you very much
 
Last edited:
Physics news on Phys.org
  • #2
Welcome to PF, KraYzie. Please note that for homework problems, we ask you to show your work before we can help you.

Do you have any thoughts on the questions?
 
Last edited:
  • #3
for #1 I used W = Fd. I changed the .5cm to .005m but i quite cannot get the answer.

I have no clue about #3 :(
 
Last edited:
  • #4
KraYzie said:
for #1 I used W = Fd. I changed the .5cm to .005m but i quite cannot get the answer.

This isn't showing your working; it is a stating one brief point. How do you intend to use work to solve this problem?
I have no clue about #3 :(
Well, to start with, do you know any equations relating power and force?
 
  • #5
yeah I know P = W/T

for #2, I have this answer written down which is C but I don't know how I got it because I just punched numbers into the calculator omg I'm so screwed
 
  • #6
can somebody really help me? I have been trying since yesterday. Please
 

1. What is the purpose of using "I" in scientific problems?

The use of "I" in scientific problems is to indicate the subjective perspective of the researcher or scientist. It allows the researcher to take ownership of their work and findings, while also acknowledging that their interpretation may be influenced by personal bias or experience.

2. Is using "I" considered acceptable in scientific writing?

Yes, using "I" in scientific writing is generally accepted as long as it is used in a consistent and appropriate manner. It is important to check with the specific style guide or guidelines of the publication or institution you are submitting your work to.

3. Can "I" be used in all types of scientific writing?

While "I" is commonly used in research articles and personal communication, it may not be appropriate for certain types of scientific writing such as reports or technical documents. It is best to follow the guidelines of the specific publication or institution for which you are writing.

4. Are there any alternatives to using "I" in scientific writing?

Yes, there are alternative ways to express the subjective perspective of the researcher, such as using passive voice or third person pronouns (e.g. "the author" or "the researcher"). However, using "I" can often provide a more direct and concise way to convey the researcher's perspective.

5. How can I ensure that I am using "I" correctly in my scientific writing?

To ensure correct usage of "I" in your scientific writing, it is important to carefully proofread and edit your work. Additionally, seeking feedback from colleagues or consulting a style guide can help you to use "I" appropriately and effectively in your writing.

Similar threads

  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Introductory Physics Homework Help
Replies
7
Views
621
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
33
Views
6K
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
Back
Top