What would happen to the the 5.98e24 kg Earth?

  • Thread starter Thread starter sensesfail
  • Start date Start date
  • Tags Tags
    Earth
Click For Summary

Homework Help Overview

The problem involves calculating the effect on the Earth’s motion if 270 million people in the US jumped simultaneously, applying a force to the Earth. The subject area includes concepts of force, momentum, and mass in a physics context.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the initial calculations regarding force and momentum, with some questioning the inclusion of the total number of people and its impact on the overall momentum. There are attempts to clarify the relationship between the forces exerted by the people and the resulting motion of the Earth.

Discussion Status

The discussion is ongoing, with participants providing feedback on each other's calculations. Some guidance has been offered regarding the relationship between the momentum of the people and the Earth, but there is no explicit consensus on the correct approach yet.

Contextual Notes

Participants are navigating the constraints of the problem, including the need to account for the total number of people and the forces they exert. There is an emphasis on understanding the implications of momentum conservation in the system.

sensesfail
Messages
8
Reaction score
0

Homework Statement



If 270 million people in the US jumped in the air at simultaneously, pushing off Earth with an average force of 800 N each for a time of 0.10 seconds, what would happen to the the 5.98e24 kg Earth? Show calculation that justifies your answer.

Homework Equations



F = mv/t
p = mv

The Attempt at a Solution



F = 800 N
t = 0.10 s
m = 5.98e24 kg

800 = (5.98e24 * v) / 0.10

v = 1.3378 e -23

p = 5.98e24 * 1.3378e-23
p = 80 kg*m/s
 
Physics news on Phys.org
Thats almost right. You forgot the 270 million bit.
 
chaoseverlasting said:
Thats almost right. You forgot the 270 million bit.

so do i just times 270 mil by 80?
 
Not quite. F=dp/dt, dp=Fdt. Total change in momentum is zero for the system, therefore,
p(e)=p(people).

This gives p(e)=(270e6)*800*0.1. From this you find the velocity of earth.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
Replies
11
Views
3K
  • · Replies 16 ·
Replies
16
Views
1K
Replies
11
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 18 ·
Replies
18
Views
3K