All Questions
44
questions
0
votes
1
answer
70
views
What would be the Earth acceleration in the units where $\hbar=c=1$? [closed]
In my calculations, I have to use the units in which the Planck constant and light velocity must be taken as unity.
Now, what would be the value of Earth's gravitation force $\implies g = G\cdot\frac{...
- 101
0
votes
1
answer
39
views
Body free fall calculation of the time durance as a direct derivation by time (non-relativistic)
Let's assume a body in free fall during 16 meters without resistance and I'd like to directly calculate the time of this fall.
Sure, one could painfully calculate:
$v^2 = 16 m·9.81 \frac{m}{s^2}$
$v = ...
- 282
-1
votes
1
answer
139
views
What's the answer to this differential equation of a ball rolling in a semi-circle [closed]
Salute, everyone.
Let's assume a ball with a mass $m$ starts falling from the top of a frictionless semi-circular hole in the ground whose radius is $r$.
From Newtons second law, we have:
$$P_x = ma$$
...
-1
votes
1
answer
135
views
Would a chess board fall faster than the chess pieces?
So if they were both falling in air, would the chess board fall faster since it's heavier?
2
votes
1
answer
94
views
What is the gravitational field in the middle of a thin rod?
I just calculated the gravitational field on the $x$-axis created by a thin rod of mass $M$ and length $L$ by applying the formula:
I got this:
However there are some issues that I don't get. If I ...
4
votes
3
answers
378
views
What are the magnitudes of the acceleration of the falling balls B and C relative to A? (Need help with binomial approximation)
I'm mostly having a problem incorporating the approximation. My trouble is towards the bottom of the post, but I wrote down all of my steps just in case I made an error somewhere.
So in this question ...
- 158
-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
777
views
Calculations of Earth falling into the Sun if it suddenly stopped orbiting? [duplicate]
If the earth stopped orbiting the sun, it would be pulled by the Sun's gravity and fall into it. How much time it will take is tricky as force is inversely proportional to square of distance.
So I ...
- 15
0
votes
1
answer
27
views
Can we have acceleration in this problem? [closed]
Two masses of equal length are attached to each other with a rope over a frictionless pulley. One of the masses is on an incline surface of 40 degrees. Supposing that the only forces on the masses are ...
- 111
1
vote
1
answer
884
views
Calculating the position of an object given object's initial position and velocity influenced by given acceleration vectors [closed]
The red circle is being pulled by two gravity points. Assume that the red circle has a given position (x,y) and a given velocity (vx, vy).
I need to calculate the velocity and position of the red ...
- 11
0
votes
3
answers
166
views
What is the four-acceleration for Newtonian gravity?
I know that Newtonian gravity is not Lorentz invariant, however, I'm just interested in the result.
Let's say we have a four-velocity, $U^\mu$, to get four-acceleration we differentiate with respect ...
- 775
1
vote
1
answer
47
views
Calculating a free fall vector so its equals to its inverse vector while accounting for gravity
I'm a game developer, and I've been struggling with a kinematics problem in the development process of my current project.
I have some stationary objects that are suddenly affected by gravity after a ...
- 13
0
votes
2
answers
111
views
How does the gravitational acceleration on a surface of planet change, if its radius shrinks while retaining the same mass? [closed]
If the radius of the earth were to shrink by $1$%
while its mass remained the same,
then how would the acceleration due to gravity on the earth's surface increase by $2$%?
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
...
1
vote
3
answers
516
views
Question about drop tower deceleration
I have a really basic question.
If we release an object from a drop tower $700\, \mathrm{m}$ tall, the object free falls for $500\,\mathrm{m}$ and reaches a velocity of $99\mathrm{\frac{m}{s}}$.
For ...
- 25