Gravitational Field: What Would Happen?

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SUMMARY

This discussion explores the hypothetical scenario of Earth gradually stopping its rotation while maintaining its gravitational field. Key points include the significance of deceleration rates, with 0.2 - 0.5g being easily noticeable to humans, and the centripetal force calculations necessary to understand the effects on objects at the Earth's surface. The centripetal force formula, F = mv²/r, is highlighted for calculating the forces acting on a 1kg object at the equator. The conversation emphasizes the impracticality of such an experiment due to potential catastrophic consequences.

PREREQUISITES
  • Understanding of centripetal force and its formula (F = mv²/r)
  • Basic knowledge of gravitational forces and acceleration (g force)
  • Familiarity with SUVAT equations for motion analysis
  • Awareness of Earth's rotation and its effects on objects
NEXT STEPS
  • Research the effects of deceleration on human perception of motion
  • Learn about gravitational forces and their impact on objects at different latitudes
  • Explore centripetal force calculations for various masses and speeds
  • Investigate the implications of Earth's rotational changes on ocean currents and climate
USEFUL FOR

Physicists, educators, students studying motion and forces, and anyone interested in the effects of planetary rotation on everyday life.

LeoPedranjo
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Hi guys!

What would happen to objects on the Earth's surface if it SLOWLY stopped spinning and Earth's gravitational field was kept as always.

Thx
 
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Hi welcome to PF

what do you think would happen ?
consider the difference of when you are in a car that stops quickly or slowlyDave
 
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davenn said:
Hi welcome to PF

what do you think would happen ?
consider the difference of when you are in a car that stops quickly or slowlyDave

Considering Earth's dimension, if it lost the angular momentum slowly due to somenthing we woundn't notice, right?
 
correct ...

Im not sure of the maths offhand, maybe some one else can chime in and
give info on how slow the deceleration would be before it wasn't noticeable
 
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davenn said:
c
Im not sure of the maths offhand, maybe some one else can chime in and
give info on how slow the deceleration would be before it wasn't noticeable
The Earth's rotation is slowing and we have noticed.
 
Yeah, different meanings of "noticeable". :)
 
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jbriggs444 said:
The Earth's rotation is slowing and we have noticed.

indeed as with good instruments

nasu said:
Yeah, different meanings of "noticeable". :)

uh huh
so I wonder what would be the necessary deceleration to be humanly noticeable to the avg person ?

0.2 - 0.5g is easily noticeable with earthquake motion
 
davenn said:
so I wonder what would be the necessary deceleration to be humanly noticeable to the avg person ?

0.2 - 0.5g is easily noticeable with earthquake motion
Can you imagine the kind of ocean current you could get from something as tiny as 0.01 g? Goodbye, California.
 
LeoPedranjo said:
What would happen to objects on the Earth's surface if it SLOWLY stopped spinning and Earth's gravitational field was kept as always.
The centripetal force needed to keep an object of mass m on a circular path of radius r and at a speed v is given by F = mv2/r
Put in the numbers for an object of 1kg on the Earths Equator and the speed (all that data is readily available) and you can calculate the force. Compare that with the weight force (approximately 10N per kg) and that will tell you whether or not we would "notice" it. It will relate to the difference in the Weight of an object at the N Pole and at the Equator.

You could also, using the SUVAT equations, find out how quickly you could bring the Earth's rotation to a halt if you wanted the effect to be 1. Noticeable and 2. low enough so that things don't go flying off the table or buildings topple over. You can make up your own numbers for the acceleration (negative acceleration, of course) for those two conditions i.e how much g force?

It's just as well that it's not an experiment that we could ever do. If it were possible then some damned fool could just possibly try it. :))
 

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