What Would Happen to Gravity If Earth Stopped Spinning?

  • Context: Undergrad 
  • Thread starter Thread starter Pengwuino
  • Start date Start date
  • Tags Tags
    Earth Spinning
Click For Summary

Discussion Overview

The discussion explores the hypothetical scenario of Earth stopping its rotation and its gravitational effects on people. It includes calculations related to centripetal force and the perceived strength of gravity at the equator, as well as considerations of inertial forces resulting from such a sudden stop.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions the gravitational effects on people if Earth stopped spinning, suggesting a relationship between gravitational force and centripetal force.
  • Another participant provides a calculation of centripetal acceleration at the equator, concluding that without Earth's rotation, gravity would feel only slightly stronger (1.0035 times) than it does currently.
  • A later reply acknowledges a previous misunderstanding and expresses gratitude for the clarification.
  • Another participant emphasizes that while centripetal force is minor compared to gravity, the inertial force from a sudden stop could have significant consequences, humorously referencing the dangers of high-speed impacts.

Areas of Agreement / Disagreement

Participants generally agree that the centripetal force due to Earth's rotation is minor compared to gravitational force. However, there is a mix of humor and concern regarding the implications of inertia if the Earth were to stop rotating, indicating a lack of consensus on the broader consequences.

Contextual Notes

The discussion includes calculations that depend on specific assumptions about Earth's rotation and position, which may not account for all variables involved in such a scenario.

Who May Find This Useful

Individuals interested in physics, particularly those curious about gravitational effects, centripetal force, and the implications of rotational motion on Earth.

Pengwuino
Gold Member
Messages
5,112
Reaction score
20
What would be the gravitational effects on people if this happened? I figure gravitational force - centripetal force = 9.8m/s^2... so is the gravitational force much stronger then 9.8?
 
Astronomy news on Phys.org
You can see here that the formula for the centripetal force is [tex]F = mv^2 / r[/tex], so the centripetal acceleration would be [tex]v^2 /r[/tex]. Here, v is the circumference of the Earth divided by the rotation period of the Earth (assuming you're standing at the equator), or 2*pi*r/(86400 seconds) , so squaring this and dividing by r gives 4*pi^2*r/(7.46496*10^9 s^2) = 0.034 meters/second^2. So, if the Earth wasn't rotating gravity would only feel about 1.0035 times as strong as it does now at the equator, not a noticeable difference.
 
Oh pff... guess i was wrong :D thanks!
 
Jesse has it right. The centripetal force due to Earth's rotation is minor compared to gravity. The inertial force, on the other hand, might be worrisome were the Earth to suddenly stop rotating. Buckle up. According to the Surgeon General, slamming into a mountain at ~1000 miles per hour can be hazardous to your health.
 

Similar threads

High School What is the shape of an asteroid impact on Earth?
  • · Replies 3 ·
Replies
3
Views
2K
High School 'A Brief History of Time' question on gravity
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad What Could Cause the Earth's Rotation to Dramatically Slow Down?
  • · Replies 39 ·
2
Replies
39
Views
8K
High School The Sun's Influence on the Moon's Orbit: Is it Negligible?
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Gravity inside an exponential mass disk
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad Why does the core collapse happen so fast in a supernova?
  • · Replies 3 ·
Replies
3
Views
4K
High School Trying to understand orbiting objects in space
  • · Replies 8 ·
Replies
8
Views
4K
Undergrad Upper limit of relativistic spin?
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Rotation rates of planets seem odd?
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad Comparing the formation of the atmospheres on Earth vs Venus
  • · Replies 1 ·
Replies
1
Views
2K