All Questions
14
questions
1
vote
3
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75
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How much time does it take for an object to fall from space? [closed]
Let's say there's an object of mass $m$ in space, $h$ meters away from the surface of the Earth. $h$ is large enough that $g$ cannot be assumed to be constant. The acceleration varies according to ...
- 117
0
votes
2
answers
167
views
Angle of projection for the minimum time of flight for a given range
If a projectile has to cover a fixed range under gravity, then what should be the angle of projection for the total time of flight to be minimum?
The initial and final point of the projectile are both ...
- 33
1
vote
0
answers
33
views
Difference between geodesics on surfaces and paths under gravitiational fields
Sorry for the maybe silly question, but I'm a math student and I'm not able to find the answer to this question from the physics point of view.
Let us suppose that a ball is set in a non equilibrium ...
- 111
-1
votes
4
answers
125
views
Initial velocity of a body when the distance travelled by it in the last second before reaching its maximum height is $5\ \textrm{m}$ [closed]
I stumbled upon this problem recently, and it has been haunting me for more than a day at this point. The question is as follows:-
When a ball is thrown up, it reaches a maximum height of $h$, ...
- 103
0
votes
1
answer
174
views
Inertia of an elevator
Imagine a situation where we have a relatively light empty elevator moving up at a pretty high constant velocity say something above $10\ m/s$, just so that it has a considerable amount of momentum ...
1
vote
5
answers
162
views
Conflicting intuitions about free fall
So I just started studying physics recently, and I came up with a question that I'm not sure how to solve, and I think it may be because of some fundamental misunderstanding. I don't want anyone to ...
- 23
1
vote
1
answer
123
views
The behaviour of acceleration of a ball in motion
I have a few doubts on how the acceleration of a ball works when we throw it up in the air, In my mind, I could imagine it in some different "real world" cases, So I am listing them all down,...
- 209
0
votes
1
answer
542
views
State space of free falling object is time variant?
In the case of a free fall object, if $h$ denotes distance from floor and $v$ the speed, then, given an input $U = g$, and $X=[h \quad v]^T$ and $\dot{X}=[\dot{h} \quad \dot{v}]^T$, I found that the ...
0
votes
4
answers
1k
views
Acceleration due to gravity during its journey up and down
When we throw an object up into the air, ignoring air resistance, etc, we define acceleration to be -9.8 m/s^2. When it goes down after its journey up, like a parabola, do we define the acceleration ...
- 23
1
vote
1
answer
114
views
Beads on a frictionless frame of wire [closed]
I was doing a physics problem and though I have the solution, I have derived a general result which I would like to get verified. I will state the problem here :
Two beads q1, q2 of equal mass m can ...
- 73
2
votes
2
answers
695
views
Is the magnitude and direction of gravity on an object the same as the objects vertical velocity?
I need to make a diagram for an entry level college physics class. I need to show the magnitude and direction of gravity on a flying object and also show the magnitude and direction of the objects ...
- 21
9
votes
2
answers
2k
views
Non-Constant Acceleration due to Gravity
Recently, I had the first physics lab for my university physics course. This lab was fairly simple, as we were merely using a computer and a distance sensor to graph the position, velocity, and ...
- 93
-2
votes
1
answer
907
views
Simple pendulum and planet mass [closed]
A simple pendulum, $20cm$ in length, has the period of $2.7s$ on a certain planet. Find the mass of the planet if its diameter is $18000km$. $G=6.67\times10^{-11}Nm^2/kg^2 $
I have no idea how to get ...
- 99
1
vote
2
answers
939
views
Why does gravity assist transfer twice the planet's velocity?
In orbital mechanics and aerospace engineering a gravitational slingshot (also known as gravity assist manoeuver or swing-by) is the use of the relative movement and gravity of a planet or other ...
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