All Questions
Tagged with newtonian-gravity projectile
200
questions
3
votes
2
answers
6k
views
The trajectory of a projectile launched from a hilltop
Here is the problem:
A boy stands at the peak of a hill which slopes downward uniformly at angle $\phi$. At what angle $\theta$ from the horizontal should he throw a rock so that it has the greatest ...
- 207k
-2
votes
5
answers
106
views
When an object is thrown towards the sky it starts to gain potential energy, why?
I didn't think so because when an object is thrown towards the sky it already has kinetic energy and it looses it's energy due to the gravitational force of the earth.
When the object looses all of it'...
- 6,217
30
votes
2
answers
3k
views
Error concerning projectile motion in respected textbook?
In the textbook Fundamentals of Physics by R. Shankar of Yale Open Courses, appears the following assertion pertaining to a car driving off a cliff, which seems correct:
This is exactly how long it ...
- 707
0
votes
0
answers
52
views
Rocket equation non-constant gravity
I am currently trying to teach myself differential equations and wondered about the following problem.
You have an object (a rocket of constant mass $m_r$) and initial velocity $v_0$ that tries to ...
- 253
2
votes
1
answer
43
views
Trajectories of projectile based on different speeds of projection [duplicate]
So my teacher was teaching gravitation and an interesting fact that he mentioned was the trajectory of a projectile projected from Earth at a speed equal to escape velocity, is parabolic.
Also, he ...
- 864
2
votes
4
answers
2k
views
Projectile/orbital motion over very long distance
We know the optimum angle for greatest horizontal displacement when launching an object with projectile motion is 45 degrees.
How to solve the angle when it is real long distance around the earth ...
- 3
1
vote
2
answers
83
views
Dropping a stick down with an angle
Let's say that we drop a stick down with an angle, meaning that the stick is not parallel to the ground. Assume there is only gravity. Is it correct that the orientation of the stick will not change ...
- 1,045
0
votes
1
answer
44
views
Terminal velocity gravity against first-order drag force
Let's say that we have a falling object with two forces acting on the object:
gravity $F_g = mg$ and a first order drag force $F_d = kv$.
Terminal velocity will be reached when gravity is equal to the ...
- 207k
7
votes
7
answers
3k
views
How do objects reach terminal velocity?
I understand the basics of this principle: the force of gravity acting downward on an object becomes equal to the air resistance acting upward on the object because as the object speeds up, air ...
- 50.2k
2
votes
3
answers
50
views
Constant speed (at terminal velocity) and zero $g$
I have read the question What would a person experience in a free-falling elevator in a shaft long enough to reach terminal velocity? here and the answer was that you feel exactly the same if the ...
- 41.1k
69
votes
7
answers
12k
views
Why do archery arrows tilt downwards in their descent?
In the movies, arrows shot into the air rotate so that during the descent, the arrow head hits ground first. What is the source of this angular momentum? It would seem that the bow string exerts a ...
- 6,217
1
vote
3
answers
88
views
How does a mass ejected at escape velocity keep moving till infinity?
I've studied that if a mass is ejected from the surface of the Earth at 11.2 km/s (or at any point above the surface at a lower Ve), it 'escapes' to infinity.
Does that not imply a violation in the ...
- 207k
1
vote
1
answer
109
views
Projectile of an object thrown from rotating planet
Last night I couldn't sleep for some time because of thinking this problem. The starting point of this problem was actually "If we were to jump perfectly vertically on earth, would we land on the ...
- 38.7k
0
votes
0
answers
48
views
Problem on orbital motion
Let's say an object is thrown from Earth with a speed of v at an angle $\theta$. An ellipse is formed with the center of Earth as its foci(given in the figure).
We know that $v_x^2=2GM(\frac{1}{r_x}-\...
- 424
3
votes
1
answer
267
views
Does something similar to a gravitation impulse exist?
Let there be a block of mass $M$ sitting on top of a table. there is a hole in the table right under the center of mass of the block.
A bullet of mass $m$ is shot through this hole and it hits the ...
- 57.2k