The velocity tag has no wiki summary.
4
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4answers
253 views
Terminal velocity of all falling objects is same?
Ideally 2 objects of different mass and weight will hit the floor at same time because they face same gravitational pull and accelerate. Will the terminal velocity of both objects be same also? and ...
1
vote
0answers
46 views
Is there any place you can safely skydive without a parachute?
While trying to explain to someone how a kitten walked away from a fall from a skyscraper I got to wondering if there's any place a human could do that and I find myself out of my depth.
The only ...
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0answers
33 views
calculate distance in feet using time interval from iphone camera [duplicate]
i am working on iPhone application to achiever the below functionality.
i want the distance in feet between Two Points from the below information.
i am standing at one position with iPhone (Camera ...
0
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1answer
43 views
Difference between velocity vectors, relative speed
Consider two particles moving in the same direction instantaneously but one of them follows a circular path and one follows a straight path.
If I adopt a rotating frame of reference in which the ...
0
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1answer
39 views
Relative Velocity problem
I was solving many problems on relative velocity and observed that when the question asks,
"what is the minimum time taken by the boat/man to cross the river.?"
so the solution says that he ...
7
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9answers
6k views
Why does the mass of an object increase when its speed approaches that of light?
I'm reading Nano: The Essentials by T. Pradeep and I came upon this statement in the section explaining the basics of scanning electron microscopy.
However, the equation breaks down when the ...
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0answers
38 views
A space vehicle travelling at a velocity of 1296 (km/h) separates by a controlled explosion into two sections of mass 7276 (kg) and 236 (kg) [closed]
A space vehicle traveling at a velocity of 1296 (km/h) separated by a controlled explosion into two sections of mass 7276 (kg) and 236 (kg). the two parts continue in the same direction with the ...
-2
votes
1answer
37 views
How to smooth a path (and speed calculation) based on randomly timed coordinates? [closed]
first my actual problem. then my try on improving the current way of solving this with the wish for feedback or even a solution :)
gpx file with lat/long, elevation and time. wanna calculate speed... ...
0
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2answers
122 views
How can I add an acceleration vector to a velocity with a different direction?
I am in my last year of high school and am struggling with some homework. I'm sorry if this question is incredibly stupid, but I simply can't find the answer in my notes.
If I have an object with a ...
0
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1answer
38 views
Why pulse waves results in wave packets?
I was doing experiments of measuring sonic velocity and I generate pulse waves from sensor 1, but when they are received by sensor 2, I saw wave packets on the oscilloscope, can you explain why?
I was ...
4
votes
2answers
92 views
What's the physical difference between the quantities $\langle v_{i}v_{j}\rangle$ and $\langle v_{i}\rangle\langle v_{j}\rangle$?
What's the physical difference between the quantities $\left\langle v_{i}v_{j}\right\rangle $ and $\left\langle v_{i}\right\rangle \left\langle v_{j}\right\rangle $?
Where $\left\langle ...
-2
votes
1answer
53 views
Why is there no such thing as a body in a state of acceleration?
It appears that velocity is a quantity of motion meaning that all objects can have assigned to them a particular velocity. Through the application of forces (ex: gravity, E&m) we measure changes ...
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1answer
54 views
man walking in rain:relative velocity
A man walking in rain at a speed of 3kmph find rain to be falling vertically. When he increases his speed to 6 kmph, he finds rain meeting him at an angle of 45 deg to the vertical. What is the speed ...
0
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0answers
13 views
Determining the acceleration of one to another with three unknowns [closed]
Given the following image, how would you determine the acceleration of block A, and the acceleration of block B relative to A? I'm trying to include the pulley as part of block A but I cannot figure ...
-1
votes
1answer
87 views
Acceleration, velocity and speed
It is given that acceleration is constant, so can we infer that average speed and velocity are the same?? Moreover, circular motion is out of the question, as the function of x(t) where ...
2
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3answers
139 views
Why do people claim electrons are accelerating
A lot of text books mention that one of the reasons that classical mechanics failed to explain atomic and subatomic processes is that electrons which accelerate should release energy in the form of ...
1
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2answers
124 views
Functions of Time
1) Is position a function of time only or also velocity? Likewise, is velocity a function of time only or also the position?
2) The following are functions of time:
$s(t)$ = distance a particle ...
-1
votes
1answer
73 views
Elevator acceleration and velocity equation [closed]
I have a small question about the velocity and the acceleration of elevators.
I am looking for equations which is for a constant velocity and acceleration ( for exemple some elevators didn't have a ...
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3answers
93 views
Parachute in vacuum
Consider that the earth is vacuum. Consider a person of weight 100 kg is falling from sky with an parachute . He is free falling at height of 3000 m. When will he reach the ground? What would happen ...
2
votes
1answer
98 views
Need help with the position of a particle in a velocity-versus-time graph
I am having trouble with a velocity-versus-time graph. I recently took a Physics test that asked this question: The graph shows the velocity versus time for a particle moving along the $x$ axis. The ...
0
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2answers
184 views
What's the acceleration of pendulum when velocity is zero
For a pendulum which has a light string to hang a bob, I know that when the bob swing to the leftmost or rightmost end, the velocity of the bob is zero and the acceleration should be maximized. But if ...
0
votes
1answer
84 views
Kinematics with non constant acceleration
A particle experiences an acceleration described by
$$
a=kx^{-2}
$$
where x is the displacement from the origin and k is an arbitrary constant.
To what value does the velocity v of the particle ...
1
vote
2answers
75 views
Gravity mitigated by velocity regardless of mass?
We know that a small object moving fast enough can pass by a planet and escape its gravity. Would this be (theoretically) true in reverse? Meaning a planet moving fast enough past a stationary smaller ...
5
votes
2answers
253 views
Explanation that air drag is proportional to speed or square speed?
A falling object with no initial velocity with mass $m$ is influenced by a gravitational force $g$ and the drag (air resistance) which is proportional to the object's speed. By Newton´s laws this can ...
1
vote
2answers
114 views
Calculating Average Velocity
I understand that the concept of an average of a data list means finding a certain value 'x', which ensures that the sum of the deviations of the numbers on the left of 'x' and on the right of 'x' ...
0
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3answers
228 views
Deriving equations of motion using integration
Please refer to my school textbook pg48 (of the book, and not the pdf counter) here: http://ncertbooks.prashanthellina.com/class_11.Physics.PhysicsPartI/ch-3.pdf
My doubt is in this context: (right ...
6
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6answers
422 views
How low can an electron go?
Title says it all - recently I encountered a strange homework exercise on de Broglie dual theory with an electron wavelength of few millimeters - which implies the velocity lower than 1 m/s. I ...
0
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3answers
117 views
Force with zero acceleration [duplicate]
If I apply a force on a body which is kept against a wall, then the body will not move. The body is not moving means that its velocity is zero, and hence its acceleration is also zero. According to ...
0
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0answers
62 views
An unmarked police car passed by a speeding car [closed]
Hi I'm trying to solve the problem
An unmarked police car traveling at a constant speed of 95 km/h is passed by a speeder traveling at 140 km/h. Precisely, 1.00 s after the speeder passes, the ...
1
vote
4answers
213 views
Light traveling through a medium
Does the frequency of light change when it travels across an interface between two media? What happens to the light wavelength and the light velocity at the interface?
I've gotten different answers ...
2
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2answers
98 views
Where are we : On level ground or on a ramp - moving in a train?
Let's say we are traveling in a train. The path has two parts: one at ground-level and the other moving up on the ramp. The ramp has an inclination of $\arctan\frac{a}{g}$ with the horizontal, where ...
0
votes
2answers
82 views
Do you use the magnitude equation to get speed from an accelerometer?
A guy suggested to me that getting speed from an accelerometer required the use of this equation:
$\text{speed} = \sqrt{x^2 + y^2 + z^2}$
This does not make any sense to me, all that you would get ...
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2answers
66 views
Conservation of Momentum from Recoil Speed
A gun has a recoil speed of 2 m/s when firing. If the gun has a mass of 2kg and the bullet has a mass of 10g (0.01 kg) what speed does the bullet come out at?
The gun has zero total momentum before ...
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vote
3answers
2k views
How do you find the velocity function of a mechanical wave?
With the form $y(x,t)=A\sin(kx-\omega t+\phi_0)$, there are two variables, How do I find the velocity? I don't know I can apply derivative with two variables.
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4answers
1k views
What is the general formula for a trebuchet?
What I'm really looking for is a formula for a trebuchet that I can input the desired initial velocity after launch and mass of the object, and from that figure out how long the long arm, short arm, ...
0
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1answer
416 views
Finding the force of friction of a moving object and its change when it accelerates to a constant speed
I have been searching for a straight forward answer to this question for ages now and it is driving me crazy.
Here is what I know:
If an object is moving at a constant speed the force of friction ...
6
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8answers
483 views
Can you completely explain acceleration to me?
I understand what acceleration is, and I know the formula, and I understand it's a vector.
I just don't understand how the equation works exactly. I'm kind of picky, I know, but bear with me.
...
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2answers
332 views
Determining Maximum Velocity of an object traveling horizontally
I'm in the process of working on a physics related game. I'm looking to find the maximum velocity of an object given it's mass and the force acting on it when it is traveling horizontally. I believe ...
6
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4answers
753 views
Double light speed
Let's say we have 2 participles facing each other and traveling at speed of light
Let's say I'm sitting on #1 participle so in my point of view #2 participle's speed is c+c=2c, double light speed? ...
5
votes
1answer
88 views
Aircraft nose-up glide
In the pilot's introductory book "Stick and Rudder" it claims that a nose-up glide is possible. It doesn't state how, why or when. It implies it's possible to do and maintain a constant forward ...
3
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1answer
105 views
Does a fly get brought up to speed with a bus?
Consider a scenario where a bus is moving at a constant speed and a fly enters through a window,the fly is also flying at a constant speed.
Since the bus is not in contact with the fly and neither is ...
1
vote
0answers
48 views
A 0.1kg ball of dough is thrown up with a velocity of 15m/s. What is the momentum halfway up? [closed]
I know that $p=mv$ and (0.1kg)(15m/s)=1.5 kg m/s and the momentum at the vertex is 0, but what is the momentum halfway up?
5
votes
3answers
360 views
What is the difference between impulse and momentum?
What is the difference between impulse and momentum?
The question says it all...I know the second of of them is mass * velocity, but what is the first one for, and when is it used? Also, what are its ...
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votes
1answer
250 views
How does Baumgartner slow his velocity so that the parachute can open up?
How does Baumgartner slow his velocity so that the parachute can open up?
What is Baumgartner's speed just before his parachute opens?
What causes his speed to slow down just before the chute opens?
...
3
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3answers
195 views
Is velocity quantized?
If velocity is not quantized, then do moving objects have 'infinitely decimal place' velocities which we just can't measure to infinite decimal places? From my understanding the quantization of ...
0
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0answers
79 views
Physics about plane take off simple find the acceleration problem [closed]
This was on my test, but I kinda botched it I think.
I was trying to use
V^2f = Vo^2 + 2a(delta x)
A plane must reach 226km/h to take off. Runway is 2000m. What's minimum acceleration needed? ...
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0answers
38 views
Truck driven from a small motor that can carry a heavy load, yet can travel fast.
I am building a truck from trash as materials. I have one small motor and a a few small gears, but no other engineered materials are allowed. The truck must carry a load for a distance of 3m. The ...
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6answers
545 views
When driving uphill why can't I reach a velocity that I would have been able to maintain if I started with it?
Consider these two situations when driving on a long straight road uphill:
Starting at a high velocity $v_h$, which the car is able to maintain.
Starting at a lower velocity $v_l$, and then trying ...
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0answers
186 views
Is there an easy derivation of relativistic velocities addition and relativistic doppler shift?
Is there an easy derivation of relativistic velocities addition and relativistic doppler shift?
I'm looking for some easy derivation of the above. Like this ...
1
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2answers
87 views
Escape Velocity question
I would like some help in understanding the derivation of the formula for escape velocity.
Why does $t$ approach infinity? And why is $v(t)$ approaching zero?
I know that $r(t)$ is infinite because ...
