All Questions
56
questions
0
votes
1
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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 ...
- 665
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 ...
- 665
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 ...
- 539
0
votes
1
answer
39
views
Air Friction Newton III
I have question to the Newton III Law and Air Friction.
At the free Fall of a Body there is an Air Friction, which is in oppopsite direction to the Gravitation Force. In my opinion the Body pushes to ...
- 1
1
vote
2
answers
60
views
Husband and Wife with Metal and Fabric Parachutes [closed]
Let's suppose: an open parachute made of fabric with a lady hanging below, starting from stand still, falls from 5000 meters. Another parachute made of thick metal, with the same size and shape as the ...
- 29
0
votes
3
answers
384
views
Does a slow moving object fall faster than a fast falling object?
If I have understood it correctly, air resistance is proportioal to the squared speed of an object, meaning that the faster the object is going the more affected by air resistance it is ( which must ...
- 41
0
votes
3
answers
90
views
Conceptual doubts about Force and Gravity [closed]
First Question: Force applied for a span of time.
Let's say a force $F$ is applied on an object of mass $M$.
So, the acceleration of that object in the direction of $F$, would be, $a = F/M$.
Now, if ...
- 33
0
votes
2
answers
584
views
Maximum height for Terminal Velocity to be reached for a certain mass?
I know the terminal velocity equation as:
V^2=(2mg)/((CdAp)
I also know that v^2 = u^2 + 2as. Assuming the object's terminal velocity is also its final velocity, and knowing every other variable in ...
-1
votes
1
answer
49
views
An object with mass $m$ thrown with speed $v_0$. There is gravity and air resistance. Find the speed of the object right before it falls on the ground [closed]
There is an object with mass $m$ on the ground. This object is being thrown with speed $v_0$. There is gravity and air resistance. The air resistance is given by $\vec{F}=-m\alpha\vec{v(t)}$ and $\...
- 699
0
votes
2
answers
119
views
Sign Problem When Dealing With Quadratic Air Resistance and Gravity [closed]
While dealing with an object falling vertically, and subject to quadratic air resistance, an equation of motion that is often presented is
\begin{equation*}
m\dot{v} =mg-cv^{2}
\end{equation*}
In ...
- 15
1
vote
4
answers
132
views
Can the forces change with frame of reference?
Consider a ball kept on man's head (mass $M$) on the Earth. Now supposing I throw the ball from height $h$ of tall building then why does he gets more hurt? Isn't the force still mg?
I would like to ...
- 13
0
votes
1
answer
120
views
Will arrow from traditional longbow will be dangerous if it is falling from above?
Let's imagine commonly seen in movies and video games "rain of arrows". Archers shoot up to hit enemies behind the obstacles, for example.
As Brittanica states:
“The best longbows were made of ...
- 103
19
votes
5
answers
7k
views
What happens when the drag force exceeds the weight of an object falling into earth?
Let's say a meteor is coming towards earth. It's not accelerating, but it does have an initial velocity. This meteor is shaped so it has an insane amount of drag, enough to even exceed its weight (not ...
- 301
0
votes
0
answers
300
views
Varying Gravity and Air Resistance in projectile motion
Salutations, I have been trying to approach a case about projectile motion considering variation of gravity acceleration and air resistance:
A spherical baseball with mass "m" is hit with inclination ...
- 141
0
votes
4
answers
61
views
Will component of force help the rock to move in the same velocity?
Suppose I am on the moon. So I am throwing a rock upwards in a velocity of $v$ with an angle of $a$ with the ground. Now we can divide the velocity in two components. One is perpendicular to the ...
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