About
7.3.8 Relationship between F and U; between g and ϕ
To understand how g is related to ϕ:
- Similarly, compare and in the above table.
- If we differentiate with respect to r, we will get , which has the same expression as g.
- Hence, mathematically
- To understand the meaning of observe the two graphs carefully, on the right side where r is positive, the gradient of ϕ vs r graph is positive but the value of g will be negative. And on the left side where r is negative, the gradient of ϕ vs r graph is negative but the value of g is positive. Thus,
Similarly, it can be concluded that by multiplying both sides by test mass m.
thus
7.3.8.1 Activity To do
ICT inquiry worksheet 1 (E), as well as the "G field and potential" EJS here. The HTML5 version is below, the Java worksheet customization to HTML5 is work in progress.7.3.8.2 Summary
symbol | ||
name | Field strength | Potential |
units | N kg-1 or m s-2 | J kg-1 |
meaning | Gravitational force per unit mass | Gravitational potential energy per unit mass |
quantity | vector | scalar |
equation |
towards the centre of the source mass |
|
relationship to mass | Force, = mg | Potential energy, = mϕ |
graph | ||
computer model if M = 500. | -6.67*500/(abs(r)*r) | -6.67*500/abs(r) |
relationship between g and ϕ | ||
relationship between F and U |
7.3.8.3 Model
Translations
Code | Language | Translator | Run | |
---|---|---|---|---|
Credits
This email address is being protected from spambots. You need JavaScript enabled to view it.; Anne Cox; Wolfgang Christian; Francisco Esquembre
Other Resources
- http://iwant2study.org/lookangejss/02_newtonianmechanics_7gravity/ejs/ejs_model_GField_and_Potential_1D_v8wee.jar
end faq
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