- #1
samsam
- 9
- 0
Let " d" equal the speed of dark
d = SQRT( e/m ) + 1
I am at a loss can anyone help me !
d = SQRT( e/m ) + 1
I am at a loss can anyone help me !
The Speed of Dark: Finding d with e/m
- Thread starter samsam
- Start date
-
- Tags
- Speed
AI Thread Summary
The discussion revolves around the concept of the "speed of dark," which is debated as a non-existent phenomenon since darkness is simply the absence of light. Participants clarify that the speed of light is a measurable constant, while any notion of darkness moving would align with the speed of light itself. The equation presented, d = SQRT(e/m) + 1, is compared to the established formula for the speed of light, c = 1/sqrt(e*u), leading to confusion about its validity. Additionally, there are references to experiments that slow down light, highlighting that light's speed is affected by the medium it travels through. Overall, the conversation emphasizes the distinction between light and darkness in physical terms.
- #2
samsam
- 9
- 0
Please someone help ! its for a challenge Samssin
- #3
blochwave
- 288
- 0
There's really no such thing as the "speed of dark", light is actually something, and the speed of light is the speed of that something. Dark is the lack of light.
The speed of light can be given as c=1/sqrt(e*u) where e and u are the permitivity and permeability of a vacuum(I forget which is which)and that's the only thing that looks similar to your equation
The speed of light can be given as c=1/sqrt(e*u) where e and u are the permitivity and permeability of a vacuum(I forget which is which)and that's the only thing that looks similar to your equation
- #4
Shooting Star
Homework Helper
- 1,980
- 4
samsam said:
We are more than at a loss, we are zonked or something to that effect.
samsam said:
Who is Samssin?
Please answer asap.blochwave said:
(Let the speed of darkness be 'd'.)
Suppose a region was lit by a light source. Then you switch off the light. The envelope of darkness then would proceed at the speed of light, from the has-been light source. We may call this the speed of darkness, for which slightly contradicting but well meaning formulas had been given by you two.
Hence, c=d.
- #5
samsam
- 9
- 0
Hi me again, totally lost can anyone help ?
what's that experiment when they slowed down light?
what's that experiment when they slowed down light?
- #6
belliott4488
- 661
- 1
samsam, can you tell us where all this is coming from? Who is asking you about the "speed of dark"?
As for light being slowed down, light will always travel through any medium at a speed somewhat less than its speed in vacuum. That's not a specific experiment, it's just an outcome of the way light propagates through media.
Perhaps you're referring to the recent experiments where light was effectively brought to a stand-still and stored for a short while before being released again? That's due to something called Quantum Entanglement, and cannot be explained by simple expressions from Classical Electrodynamics, such as what you seemed to be offering in your original post (although I'm still not sure what that was ...)
As for light being slowed down, light will always travel through any medium at a speed somewhat less than its speed in vacuum. That's not a specific experiment, it's just an outcome of the way light propagates through media.
Perhaps you're referring to the recent experiments where light was effectively brought to a stand-still and stored for a short while before being released again? That's due to something called Quantum Entanglement, and cannot be explained by simple expressions from Classical Electrodynamics, such as what you seemed to be offering in your original post (although I'm still not sure what that was ...
)
Neglect gravity other than that of water; neglect friction.
F1=ρgsh=1000*10*1*(1+4)=50000 N;
F1=ρgsh=1000*10*0.1*4=4000 N;
F3=50000-4000=46000 N?
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system
$$M(t) = M_{C} + m(t)$$
$$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$
$$P_i = Mv + u \, dm$$
$$P_f = (M + dm)(v + dv)$$
$$\Delta P = M \, dv + (v - u) \, dm$$
$$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$
$$F = u \frac{dm}{dt} = \rho A u^2$$
from conservation of momentum , the cannon recoils with the same force which it applies.
$$\quad \frac{dm}{dt}...
I was told forces are vectors so they can be divided into x and y components, but what about the normal force or the force of static friction? do you divide those into x and y components if say you had a block that was lying on an angled surface?
Similar threads
Hot Threads
-
Torque biomechanics
- Started by Naucus
- Replies: 6
- Introductory Physics Homework Help
-
Work Done in slowly pulling a thread
- Started by Bling Fizikst
- Replies: 28
- Introductory Physics Homework Help
-
How do you calculate the pull of this piston?
- Started by vdance
- Replies: 27
- Introductory Physics Homework Help
Recent Insights
-
Insights Why Entangled Photon-Polarization Qubits Violate Bell’s Inequality
- Started by Greg Bernhardt
- Replies: 26
- Quantum Interpretations and Foundations
-
Insights Quantum Entanglement is a Kinematic Fact, not a Dynamical Effect
- Started by Greg Bernhardt
- Replies: 11
- Quantum Physics
-
Insights What Exactly is Dirac’s Delta Function? - Insight
- Started by Greg Bernhardt
- Replies: 5
- General Math
-
Insights Relativator (Circular Slide-Rule): Simulated with Desmos - Insight
- Started by Greg Bernhardt
- Replies: 1
- Special and General Relativity
-
Insights Fixing Things Which Can Go Wrong With Complex Numbers
- Started by PAllen
- Replies: 7
- General Math
-
Insights Fermat's Last Theorem
- Started by fresh_42
- Replies: 105
- General Math