The speed tag has no wiki summary.
-2
votes
1answer
39 views
How to move an object to follow moving object?
Say you have an object moving increasing on the y axis, lets say 10 points per second to keep it simple. Then you want to have another object on x axis move in from the right, so decreasing x axis, ...
1
vote
1answer
53 views
Can a link between photons that don't exist at the same time provide communication with the past?
They have published something about a link between photons that don't exist at the same time. Does this means that it is possible to build a device that will receive messages from itself but these ...
-1
votes
1answer
45 views
What is the maximum speed of a change? [duplicate]
Is there any limit on the speed of changing something?
For example a particle is transformed to some other particle; This takes some time or is absolutely instant?
If every change takes some time, ...
-2
votes
0answers
39 views
Whats the theoretical max speed to go around the world? [closed]
I light of the new Scramjet tests I have a question thats been bogging me.
I live in Denmark, about the furthest i can travel is to New Zeeland which is roughly on the opposite side of the earth.
...
0
votes
1answer
45 views
Is there any case where one would use, snap, crackle or pop?
As we all know, if you differentiate distance with reference to time, you get speed, and likewise, differentiating speed you get acceleration. However, if you keep differentiating, to the rate of ...
1
vote
1answer
39 views
Gyro vs Accelero : Why is that assessment false?
Can we say that the Accelerometer's values are somewhat the integral of the Gyroscope's values ?
I think that because I know that the velocity is the derivative of the position with respect to time ...
2
votes
2answers
88 views
Does inertia increase with speed?
I have heard that when the speed of the object increase, the mass of the object also increase. (Why does an object with higher speed gain more (relativistic) mass?)
So inertia which is related to ...
1
vote
2answers
81 views
Currents and the Speed of Light
Why is it that currents don't flow at the speed of light, but rather significant ratios of the speed of light.
I don't have any formal reasoning as to why they would flow at the speed of light-I just ...
-5
votes
0answers
29 views
Multiplying Dimension Result [closed]
This might be a general question but I couldn't find any information on it.
If we multiply the first dimension by the second, we get area.
If we multiply by the third, we get cubic area.
What is ...
2
votes
1answer
135 views
How to find speed when accelerating down a slanted wire
I saw this picture on one of my social media sites with the caption, "I'd do this in a heart beat! Who's with me!"
I was about to go balls to the walls and say, "I'm in! When and where??" But then ...
-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... ...
-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
votes
3answers
56 views
Wind effect on driving a ground-based vehicle
A friend of mine seems to think that wind affects the ground-speed of a ground-based vehicle in the same way airspeed affects an airborne aircraft. i.e. If faced with a 10mph headwind, your car isn't ...
1
vote
1answer
52 views
B-field and Magnetic forces, speed of a particle
Let's say I have a particle moving perpendicular to a uniform magnetic field of magnitude $x \ T$, and it moves in circle with a fixed radius. How do I find the speed of this electron? Initially I ...
4
votes
2answers
1k views
Help me get out of a speeding ticket
I was driving uphill from a complete stop for a distance of .4 miles estimated to take 1 minute in a navigation app. I was pulled over right after cresting the hill. The cop had me on radar going ...
9
votes
4answers
573 views
Why does the speed of light $c$ have the value it does?
Why does light have the speed it does? why is it not considerably faster or slower than it is? I can't imagine science, being what it is, not pursuing a rational scientific explanation for the speed ...
-2
votes
1answer
68 views
Electric potential energy and speed
If we have electric field and we put electron there , the electron will move in the opposite direction as the electric field.
My question is electron in that direction will speed up or slows down ? ...
4
votes
3answers
143 views
If an electric car were to drive without having to stop, would the range be greatly affected by the speed at which the vehicle is moving?
Of course aerodynamics factors into this question, and the faster you are moving the more air you have to push out of your way, the more energy you use. But would the difference be only a small ...
-3
votes
3answers
72 views
Speed of an object in air versus in vacuum
Okay, imagine that you are shooting a rocket down a tunnel that is 60 miles long and the rocket is travelling at 60mph, so the rocket should reach the end of the tunnel in a hour, right? Yep, in an ...
0
votes
0answers
34 views
Special relativity: Related speed [closed]
If a sheep is moving in a velocity of 2mph related to a train, and the train is moving in a velocity of 2mph related to the ground what is the velocity of the SHEEP related to the ground.Is there an ...
1
vote
2answers
101 views
comparing torque and 0-60 speed in cars
Im looking a two cars, both are the same model but ones got a 2.0L turbo petrol engine and ones got a 3.0L turbo diesel engine.
These are the full specs
2.0L Petrol
3.0L Diesel
what im ...
1
vote
1answer
87 views
Weightlessness on Earth
Would the following work?
Imagine one would
1) create a straight 4000 km long tube (at ground level), following the curvature of the Earth, wide enough to hold a pod the size of an aircraft cabin;
...
5
votes
1answer
225 views
What is the speed of time
When we measure the speed of a moving element we do it with the help of a reference frame. Now if we need to measure the speed of time, is it possible? Is time really has speed?
Thanks in advance.
2
votes
1answer
189 views
Where to find the current positions and velocities of the planets?
I've written a program which simulates the motions of planets and other bodies. I'd like to run it on our own solar system, but to do so I need to know the current positions (preferably in ...
0
votes
1answer
105 views
Would an object hit the ground faster when it gets launched vertically upwards or downwards?
A while ago I had a discussion with someone about the speed of an object when it hits the ground. When does an object hit the ground faster:
When you launch the object to the sky so it can fall ...
2
votes
2answers
441 views
How can I calculate the wave propagation speed in a copper wire?
First of all: I am a computer science student, so I don't have much knowledge of physics. So please keep your answers simple.
I recently learned something about circuit design and its problems ...
0
votes
0answers
26 views
Intuitive understanding of the equation for kinetic energy [duplicate]
Possible Duplicate:
Why does kinetic energy increase quadratically, not linearly, with speed?
I know this is one of the easiest equations out there and I've used it for years but its still ...
3
votes
2answers
120 views
How to relate speed of sound with relative humidity?
I am exploring the idea of measuring the humidity of a space using sound waves, however I am having trouble finding a mathematical relationship between the speed of sound and the humidity level.
...
-4
votes
2answers
77 views
super-jump air balloon [closed]
We have the following objects:
a 80 kg person
a rope of negligible weight
a balloon filled with helium, which can lift for around the same weight, 80kg.
My question is, which of the following ...
2
votes
2answers
536 views
Why does an object with higher speed gain more (relativistic) mass?
Today, in my high school physics class, we had an introductory class on electromagnetism. My teacher explained at some point that an object with a very high speed (he said it started to get somewhat ...
0
votes
3answers
225 views
Imagining to speed up the Earth's revolution around the Sun until we feel its motion
If the Earth were revolving around the Sun much faster than it does, let's say 100 or 1000 times faster or whatever big-enough multiple of its actual speed, would we feel it? What sensation would we ...
1
vote
3answers
1k views
Is the same amount of electricity used for ceiling and table fans on different speeds?
We use ceiling and table fans in home which are can be set to low or high speeds using regulators. I want to ask that does it uses or consumes same amount of electricity at different speeds? Here, ...
2
votes
2answers
122 views
Speed of Entropy change
If time in systems moving with different speed goes differently, does speed of entropy change differ in these systems?
(is "speed of entropy change" a valid term? can we compare them?)
3
votes
1answer
159 views
Does $\lambda\nu = c$ hold for all the waves in the universe?
Are all waves in the universe the same as electromagnetic waves?
Basically, my question arises from an equation I found in my chemistry textbook:
$$\lambda \nu ~=~ c.$$
This states that the ...
7
votes
2answers
395 views
Is it possible to travel at precisely the speed of sound?
I've been talking to a friend, and he said that it's impossible to travel at exactly the same speed as the speed of sound is. He argued that it's only possible to break through the sound barrier using ...
4
votes
2answers
219 views
Why does the wheel of a car appear to be moving in opposite direction?
When a car is about to stop, the speed of its wheel reduces. Why do we see or feel that the wheel of the car is moving in the opposite direction? This can also be observed of a fan at home. So why ...
4
votes
4answers
2k views
How Felix Baumgartner has reached the speed of sound quickly
I have watched Felix Baumgartner freefall; but I wonder how Felix has reached the speed of sound quickly, in a matter of some seconds, then we had no idea of its speed?
Any explanation please.
2
votes
3answers
535 views
Why would a fat skydiver fall first in free fall?
I was having one of those obnoxious conversations with a friend where he was arguing that a fat skydiver would reach the ground faster than a skinny skydiver. To me it seemed as obvious that the world ...
0
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0answers
58 views
Refractive index outside a vacuum [closed]
Refractive index is defined as n = c/v where c is the speed of light in the vacuum and v is the velocity of the light in a given material. Therefore refractive index outside of vacuum can be any ...
2
votes
1answer
174 views
Which speed can an electric scooter reach on a given slope?
Electric scooters are always "given" as "working with slopes up to xx%", but what does it mean?
Given motor torque and power, scooter+driver weight and wheels diameter, how can I determine at which ...
6
votes
1answer
696 views
How fast would someone have to run to run over water?
I was thinking about Flash, the superhero, or the little boy in the Incredibles.
There is one Yahoo answer that doesn't answer a lot. Especially, I don't think surface tension would help a lot for a ...
-1
votes
1answer
127 views
What is the quantity in physics that is advanced from speed? [closed]
What is the quantity in physics that is advance from speed?
i know one is velocity, one is speed, one is acceleration.
0
votes
3answers
176 views
How will you measure speed in km/hr in space?
How is the speed of an object in space measured? Also more importantly how do you measure your own speed in space? On the road we use a speedometer which tells us the speed easily. How is it done in ...
0
votes
2answers
336 views
Can human hand move at a speed rate like this baseball pitch or is it just the speed of ball?
Fastest baseball pitch ever recorded was in 1974 at a speed of 100.9 miles per hour.
Does this mean that the pitcher's hand was also traveling at that speed or just the ball?
Is it physically ...
-1
votes
3answers
474 views
Relation between Newtons and Kilograms
Work is expressed as W=F*d, where the F is in Newton, d is in meters and result ...
0
votes
1answer
112 views
Someting almost faster than light traveling on something else almost faster than light [duplicate]
Possible Duplicate:
Travelling faster than the speed of light
Double light speed
Lets say that
an airplane can fly at 4/5 of the speed of light, and
I can run at 2/5 of the speed of ...
0
votes
0answers
130 views
Meeting Of 2 People On a circular track [closed]
Two persons are running on a circular track either in the same direction or in the opposite direction, indefinitely.
The speed of both of them is given to you.
Speed will be positive in clockwise ...
0
votes
3answers
363 views
Finding instantaneous speed in MPH given acceleration, RPM and gear ratio
I am still trying to figure out how to (semi) accurately model instantaneous speed after having found acceleration. I have found that at higher RPMs, the resultant acceleration will be lower. I was ...
0
votes
3answers
197 views
How to determine an exponential acceleration curve?
I've always been not so bad in mathematics, but I'm terribly bad at physics. For me, abstract concept are totally understandable, but when it come to reality, I'm lost !
So, for my job, I need to ...
3
votes
3answers
853 views
Does friction decrease as objects move faster against each other?
I was told that the faster two objects move against each other, the less the friction between them would be… compared to if they were moving slower. In physics class, we always use the coefficient of ...
