All Questions
13
questions
1
vote
1
answer
60
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Force along $x$ direction on a bumpy surface
Gravitational potential energy near earth is given by$$U(y)=mgy$$
Suppose a bumpy surface is described as $y=\sin(x)$, then $U$ varies with $x$:
$$U(x) = mg\sin x $$
Then the force along $x$ is given ...
- 908
0
votes
2
answers
50
views
Simplified formula of potential energy giving different expected value of mass
I am trying to calculate the mass of a planet by the following image
I have the mass of the object, $2$ kg, and the radius of the planet, $5000$ km (also the gravitational constant $G$).
My first ...
- 105
-1
votes
2
answers
368
views
How can a system of Atwood machine lose gravitational potential energy?
The heavier block in an Atwood machine has a mass twice that of the lighter one. The tension in the string is 16.0 N when the system is set into motion. Find the decrease in the gravitational ...
- 137
4
votes
2
answers
689
views
Why does mass increase when gravitational potential energy increases?
I saw a solved example in a book (Concepts of Physics by H.C. Verma, volume 2), where there is a body near surface of the earth, the problem is to calculate the increase in mass of the body when it is ...
- 3,160
1
vote
2
answers
335
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Relative height or height from ground?
Ok so I encountered this question ->
A 10 H.P. motor pumps out water from a well of depth 20m
and fills a water tank of volume 22380 litres at a height of 10m
from the ground. The running ...
- 19
-1
votes
1
answer
44
views
Potential and Field for a sphere with a central core of differing density [closed]
A spherically symmetric planet of radius $a$ consists of a central core of radius $b(<a)$ of uniform density $\rho_1$ surrounded by an outer region of uniform density $\rho_2$. Obtain an expression ...
- 171
1
vote
4
answers
1k
views
Gravitational potential energy defined in terms of work
An outcome of my high school syllabus is to "define gravitational potential energy as the work done to move an object from a very large distance away to a point in a gravitational field: $-GMm/r$".
...
- 91
0
votes
1
answer
287
views
Potential Energy of Interaction Between a Sphere and a Particle Formula Derivation [closed]
A sphere of radius R has density described by ρ=ρ(r). Derive equation for pontetial energy of interaction between the sphere and some point particle of mass m which is at distance r from the center of ...
- 89
3
votes
4
answers
279
views
How do I correctly introduce time into this equation?
So, for the past few years it's been my goal to create an equation that would give me the position of an object in a gravitational field at time $t$, given it's initial position and velocity. At first ...
- 145
0
votes
1
answer
1k
views
Calculating change in gravitational potential energy [closed]
A satellite mass $500\ kg$ is elevated from altitude $10000\ km$ to altitude $20000\ km$. Radius of earth is $6378\ km$. Mass of earth is $5.97 \cdot 10^{24}\ kg$. Gravity is given to be $9.81\ m/s $
...
- 109
0
votes
1
answer
5k
views
Computing average force exerted by ground when jumping
Problem: A man of mass $m$ jumps vertically into the air from a sitting position in which his center of mass (CoM) is at a height $h_1$. When his feet are just about to leave the ground his CoM is at ...
- 657
0
votes
1
answer
344
views
Statements about gravitational potential energy contradicting intuition?
So in my textbook I am told:
two masses have gravitational potential energy because work had to be done in order to move one the masses form a position very far away (lets say infinity) to the ...
- 881
1
vote
1
answer
1k
views
Derivation of the self gravitational potential energy of a sphere
I have been searching on the Internet but have not found a derivation of the formula for the self gravitational potential energy of a sphere. Can someone show how to do this? I assume it involved 6 ...
- 175