The Naked Scientists
  • Login
  • Register
  • Podcasts
      • The Naked Scientists
      • eLife
      • Naked Genetics
      • Naked Astronomy
      • In short
      • Naked Neuroscience
      • Ask! The Naked Scientists
      • Question of the Week
      • Archive
      • Video
      • SUBSCRIBE to our Podcasts
  • Articles
      • Science News
      • Features
      • Interviews
      • Answers to Science Questions
  • Get Naked
      • Donate
      • Do an Experiment
      • Science Forum
      • Ask a Question
  • About
      • Meet the team
      • Our Sponsors
      • Site Map
      • Contact us

User menu

  • Login
  • Register
  • Home
  • Help
  • Search
  • Tags
  • Member Map
  • Recent Topics
  • Login
  • Register
  1. Naked Science Forum
  2. Non Life Sciences
  3. Physics, Astronomy & Cosmology
  4. How fast am I going, relative to the Earth, when standing still?
« previous next »
  • Print
Pages: [1]   Go Down

How fast am I going, relative to the Earth, when standing still?

  • 9 Replies
  • 5853 Views
  • 0 Tags

0 Members and 1 Guest are viewing this topic.

Offline Anywho (OP)

  • Jr. Member
  • **
  • 18
  • Activity:
    0%
    • View Profile
How fast am I going, relative to the Earth, when standing still?
« on: 23/10/2012 05:16:26 »
The title sounds wrong I know, but when I am standing still I am exerting a force on the Earth which can be measured with a set of scales.

How fast would I have to be travelling in space to get the same reading on a set of scales?

Logged
 



Offline Ophiolite

  • Hero Member
  • *****
  • 822
  • Activity:
    0%
  • Thanked: 25 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #1 on: 23/10/2012 08:41:16 »
It's not a question of speed, but of acceleration.
Logged
Observe; collate; conjecture; analyse; hypothesise; test; validate; theorise. Repeat until complete.
 

Offline syhprum

  • Naked Science Forum King!
  • ******
  • 5093
  • Activity:
    9%
  • Thanked: 64 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #2 on: 23/10/2012 09:56:34 »
At relatively low speeds a power source beneath the scales would have to be accelerating you at 9.82 meters per second per second for you to get the same reading on the scales as you would get on the surface of the Earth.
Logged
syhprum
 

Offline Anywho (OP)

  • Jr. Member
  • **
  • 18
  • Activity:
    0%
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #3 on: 23/10/2012 14:09:16 »
I should have mentioned that I only want to know how fast I would have to be going to get the scales to read the same weight (force?) temporarily.

So if I weigh 100kgs on Earth, how fast would I have to be travelling to get the scales to read 100kgs in space?

I realise that in the absence of gravity the scales will only read 100kgs temporarily.



Logged
 

Offline syhprum

  • Naked Science Forum King!
  • ******
  • 5093
  • Activity:
    9%
  • Thanked: 64 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #4 on: 23/10/2012 15:33:15 »
As Ophiolite  and myself have pointed out speed is irelevant at any speed the scales would read zero unless you are accelerating
« Last Edit: 24/10/2012 09:21:44 by syhprum »
Logged
syhprum
 



Offline Anywho (OP)

  • Jr. Member
  • **
  • 18
  • Activity:
    0%
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #5 on: 23/10/2012 23:41:30 »
Quote from: syhprum on 23/10/2012 15:33:15
As Ophiolite  and myself have pointed out speed is relevant at any speed the scales would read zero unless you are accelerating

Okay, I don't think I've made myself clear, the scales are stationary and immovable, you hurl yourself at them to get a reading, how fast would you have to be going to get the scales to hit the 100kgs you weigh in Earth?

Or alternatively, if there is a pane of glass that would only just break if you were to stand on it under Earths gravity, how fast would you have to collide with the same pane of glass in space in order to break it?
Logged
 

Offline syhprum

  • Naked Science Forum King!
  • ******
  • 5093
  • Activity:
    9%
  • Thanked: 64 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #6 on: 24/10/2012 09:19:16 »
It would depend on how much the scale surface moved when you landed on it if you were moving at one meter per second and the scale surface deflected 1/9.82 meters i.e 10.183 cm your 100kgs weight would be recorded.
Logged
syhprum
 

Offline Ophiolite

  • Hero Member
  • *****
  • 822
  • Activity:
    0%
  • Thanked: 25 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #7 on: 24/10/2012 17:41:16 »
In other words what is your temporary acceleration when you hit the scale? It will be negative, i.e. a deceleration. As syphrum points out, depending upon the 'give' of the scale will depend the speed with which you need to impact the scale.

(We're not being difficult, just needfully pedantic.)
Logged
Observe; collate; conjecture; analyse; hypothesise; test; validate; theorise. Repeat until complete.
 

Offline Anywho (OP)

  • Jr. Member
  • **
  • 18
  • Activity:
    0%
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #8 on: 25/10/2012 01:14:04 »
Quote from: Ophiolite on 24/10/2012 17:41:16
(We're not being difficult, just needfully pedantic.)

I'm not being difficult either :), and I understand the points being made, but my understanding of how this works is still counter-intuitive for me so I'm trying to get it all clear.

What if the scales were of a hypothetical kind that were solid and unflexible, and the person was rigid also.

On Earth the rigid person steps onto the immovable scales and they settle on 100kgs (after initially reading more due to dynamic loading)

In space what speed would be needed for the rigid 100kg mass to temporarily read 100kgs on the unflexing scales?

I think the answer is "any speed will register more than 100kgs" which seems very counter-intuitive to me.

Would that mean that a 100kg(mass) person on the moon could not gently step onto a set of scales without it reading 100+kgs before it finally settles on 16kgs?
« Last Edit: 25/10/2012 01:15:48 by Anywho »
Logged
 



Offline syhprum

  • Naked Science Forum King!
  • ******
  • 5093
  • Activity:
    9%
  • Thanked: 64 times
    • View Profile
Re: How fast am I going, relative to the Earth, when standing still?
« Reply #9 on: 25/10/2012 07:13:58 »
A moving rigid body stopped in zero time by a completely rigid scale will produce an infinite force, of course completely rigid bodies do not actually exist.
When you step on your scales on the moon provided you step gently your velocity relative to the scale will be zero and the only force on the scale will be due to the gravitational field of the moon 
Logged
syhprum
 



  • Print
Pages: [1]   Go Up
« previous next »
Tags:
 

Similar topics (5)

What causes the Earth to have "seasons"?

Started by RobotGymnastBoard Physics, Astronomy & Cosmology

Replies: 10
Views: 11883
Last post 25/02/2009 11:27:40
by Damo the Optics Monkey
How would our weight differ on a revolving to that of a non-revolving earth.?

Started by Alan McDougallBoard General Science

Replies: 5
Views: 10091
Last post 10/08/2008 19:44:19
by Alan McDougall
Can matter and anti-matter annhilation one day power the earth?

Started by spook1456Board Physics, Astronomy & Cosmology

Replies: 1
Views: 7552
Last post 11/04/2011 17:46:33
by JMLCarter
Is the Earth immersed in dark energy and dark matter?

Started by thedocBoard Physics, Astronomy & Cosmology

Replies: 2
Views: 7029
Last post 13/08/2012 13:18:25
by lightarrow
Would increase or a drop in Sun's temperature effect Earth's temperature?

Started by bobdihiBoard Physics, Astronomy & Cosmology

Replies: 14
Views: 5051
Last post 29/07/2019 10:55:01
by andrew7278
There was an error while thanking
Thanking...
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.159 seconds with 57 queries.

  • Podcasts
  • Articles
  • Get Naked
  • About
  • Contact us
  • Advertise
  • Privacy Policy
  • Subscribe to newsletter
  • We love feedback

Follow us

cambridge_logo_footer.png

©The Naked Scientists® 2000–2017 | The Naked Scientists® and Naked Science® are registered trademarks created by Dr Chris Smith. Information presented on this website is the opinion of the individual contributors and does not reflect the general views of the administrators, editors, moderators, sponsors, Cambridge University or the public at large.