All Questions
14
questions
0
votes
3
answers
173
views
Gravitational force and centre of mass
So question goes like
"What is the magnitude of gravitation force of the particle due to rod?"
In the figure the particle is of mass $m$ and from distance $d$ from end of the rod and the ...
2
votes
1
answer
79
views
Simple Analytical mechanics problem [closed]
I am trying to solve a simple problem stated as follows:
"There are two cartesian reference frames k $(o;x,y,z)$ and K $(O;X,Y,Z)$ with the first one being still (inertial) and the second one (K)...
0
votes
1
answer
54
views
Circular motion of planet around star
The question says that the planet moves in a circular orbit around the massive star. But the graph says that velocity of the star wrt the COM of star-planet system varies with time. But my confusion ...
- 74
-1
votes
1
answer
60
views
Elevator situations
What happens to my weight when I'm in an elevator that's,
a. stationary
b. moving with a constant velocity
c. moving upwards with an acceleration a where a<g
d. moving upwards with an acceleration ...
- 801
0
votes
2
answers
451
views
Gravitational potential in a system of two particles
Suppose two particles with masses $m_1$ and $m_2$ are interacting via a central force. Lets work in the center-of-mass frame, and let $r$ be the distance from the masses to the center of mass which ...
- 273
2
votes
2
answers
292
views
Where can pseudo-force be used?
I was doing this question
and eventually got the answer but I had a thought :-
It being a non inertial frame , can we apply pseudo force on it?
But as the question says both are travelling with ...
user235632
0
votes
1
answer
120
views
Human Body Upward Acceleration on Scale [closed]
I am reviewing for a Physics exam, and have come across the following example question:
If I weigh 200 pounds, but a scale I'm standing on reads 400 pounds,
then I am accelerating upward at
1g
2g
3g
...
0
votes
4
answers
7k
views
What is acceleration due to gravity at the centre of the earth? [duplicate]
When I asked my teacher that what is the acceleration at the centre of earth, he replied that it is 0 as when we move inside the earth, the effective mass decreases i.e. the mass that exerts ...
- 592
-2
votes
2
answers
217
views
Gravitational potential energy in CM frame
If the centre of mass is taken as the origin, then the gravitational potential energy of two bodies is
\begin{equation}
V=-\frac{Gm_{1}m_{2}}{(r_{1}+r_{2})}
\end{equation}
where $r_{1}$ and $r_{2}$ ...
- 158
-1
votes
1
answer
346
views
Why $N = mg(\cos \theta) - ma_c$ and not only $N = mg(\cos \theta)$ ? (problem with box sliding on sphere) [closed]
So I've found a solution of my problem online and I don't understand a crucial part of it :
So, first, why do we consider here the centripetal force as a separate entity from the gravitational force? ...
- 1
0
votes
1
answer
4k
views
Calculating the first cosmic velocity / velocity for a circular orbit
Today in class we calculated first cosmic velocity using this equation $$G\frac{mM}{(R+h)^2}=\frac{mV^2}{R+h},$$ where $m$ = mass of the body, $M$ = mass of the Earth, $R$ = radius of the Earth, $h$ = ...
- 123
2
votes
2
answers
389
views
In this particular problem: Is the mass of the system the mass of the person?
I am doing this problem:
The upward normal force exerted by the floor is 620 N on an elevator passenger who weighs 650 N.
What is the magnitude of the acceleration?
This is how I solved it:
$$\sum F ...
- 207
1
vote
1
answer
167
views
Regarding the centrifugal force in a 3-body system
In our lecture about general mechanics, we have treated the simplified 3-body system consisting of the Sun, the Earth and the Moon. We assumed that the moon does not have any influence on the Sun or ...
- 309
0
votes
4
answers
5k
views
Why doesn't the Gravitational Force causes body to fall towards orbital center moving with constant tangential speed? [duplicate]
Suppose a satellite is orbiting the Earth. The gravitational and centripetal force supposedly point towards the Earth. Therefore, the net force is towards the Earth. Since the satellite doesn't fall ...
- 181