# All Questions

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### Value of of gravity 9.8m/sec^2 and centrifugal force [closed]

I had a doubt regarding centrifugal force on earth is not accounted in any equations as object falling towards earth.eg f=ma.i read questions asked by few about the same and got to a conclusion that ...
580 views

### Why aren't atoms affected by gravity, but molecules are?

I read this book here: http://tiny.cc/Gravity-Atom-Myth It claims that while gravity does affect individual atoms, it's not quantified like molecular mass due to lack of binding proteins which render ...
157 views

### Does the big bang violate the conservation of energy? [duplicate]

It is a fact that a thing is existing now because it had already been created. So why don't we take this to account to redefine law of conservation of energy.
178 views

### A ballpark figure on physicists [closed]

1) Out of the 7 billion+ people alive today, around how many have earned a PhD in physics? 2) Around how many physicists are working today? 3) Around how many physicists are being added to the work ...
220 views

### home made atom destruction unit [closed]

Today we learnt at school that atoms can be destructed. I believe Physics is a great science to do experiment and I would like to try it at home. Could you tell me what I need to do it? and is it ...
251 views

### Conceptual doubts in EM waves and old quantum theory [closed]

I have a few questions. I know that EM waves transfer energy. So when they are generated why do they form curves? Are energy packets moving in a curvy path, or energy packets (quanta) not considered ...
281 views

### GPS Working Principle [closed]

Hand-held GPS units in modern phones identify your location by (A) transmitting their location and time to GPS satellites. (B) receiving location data of GPS satellites. (C) ...
124 views

### Is it possible to make a light beam act like a stream of water from a spining hose? [closed]

If we had the ability to make an actuator that could turn around at or past the speed of light and I attached a high miliwatt laser to it, then spun the laser around on the actuator at the speed of ...
2k views

### man walking in rain:relative velocity [closed]

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 ...
92 views

### High School Physics student needs help [closed]

A human cannon has a spring constant of 35 000 N/m. The spring can be extended up to 4.5m. How far horizontally would a 65kg clown be fired if the cannon is pointed upward at 45 degrees to the ...
253 views

### maybe the universe has already 'ended'? [closed]

I aks you if this reasoning has a base in what we know of universe. There are many articles about so called "vacuum metastability event". As I understand this happens (can happen) with an enormous low ...
177 views

### True or false? Particle physics [closed]

It is not possible to prove the point of origin of a photon It is not possible to prove the point of origin of a free electron It is not possible to prove that protons or neutrons exist inside a ...
259 views

### What makes a space a real space?

By "real space" I mean a space in which physical particles move. Consider a color sphere and let a bunch of objects "move" on its surface. "Move" means "change colors". Let there be some rules ...
28 views

### Coefficient of Static friction [on hold]

Kindly provide the reasoning for the direction of friction chosen...
41 views

### What causes a spacecraft entering the atmosphere to catch fire? [on hold]

What causes a spacecraft entering the atmosphere to catch fire? A) surface tension of air B) viscosity of air C) high temperature of upper atmosphere D) greater proportion of ...
20 views

### How do I calculate the angle made by this falling rod? [closed]

A uniform rod of length 1 is in contact with a smooth vertical wall and a smooth horizontal floor. Initially, the rod is kept almost vertical. Now the rod is released. Find the angle made by the rod ...
18 views

### Current intensity [closed]

i want an answer for First question : a and b And Second One , Saying Why you said that answer
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### maths question on levers [closed]

Someone holds a 2kg weight in their hand at a distance of 35cm from the elbow (fulcrum) and the downward force (load) due to the weight is 20 Newtons. Calculate the effort in Newtons that the ...
138 views

### Recommended book for beginners on advanced science topics [duplicate]

I have a background in engineering so I have some familiarity with basic math and science. I've recently been reading about other topics such as Einstein's relativity and have become interested in ...
283 views

### Alternative derivation for the capacitor energy equation [closed]

I hope this is the right place for this kind of post. A friend is trying to derive the equation for the energy stored in a capacitor by analysing the change in potential on one plate when the ...
359 views

### Basic Physics Question [closed]

I'm having a difficult time answering this question. I think I'm just converting the units wrong somewhere: You're the CEO of a courier company, and you decide to select an electric car for your ...
104 views

### General Relativity and Time Dilation [duplicate]

Is time affected by the gravitational force? If so, what might be the effect on time at the centre or near centre of earth ?
8k views

### Why two balls of different mass dropped from the same height falls the ground at the same time? [duplicate]

When two balls of different masses, thrown from equal height they reaches the ground at the same time. Can anyone explain this in terms of laws of Physics(or with mathematical equations)?
86 views

### Photonics: Slab As a Lens [closed]

The question can be found here: http://gyazo.com/fc4d26cd35e6ce368ad2a8ed504f1dcc The refractive index it references can be found here: http://gyazo.com/94fd2f3b5ea7da9226c3acd56b0024c1 I'm not ...
218 views

### Is the Graveyard Really so Serious?

Calculations in relation to black holes are solely in consideration of spacetime curvature and its effects. They are in total alienation with respect to the action of inertial agents[external ...
109 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 ...
468 views

### What really is the smallest “mass” or “object” in the universe?

Look at this here. With respect to the sciences, the atom is obviously not the smallest piece of mass. Apparently, if people have already broken down the atom in to particles smaller than so, why ...
242 views

### What made up light photons? [duplicate]

mass is energy per c square $m=E/c^2$ energy is made up of photons but what made up photon itself? what made up a single photon? Replay to comment: but as we can see in history early phyisicists ...
833 views

### Is antigravity the source of accelerating expansion (dark energy)?

Is antigravity the source of accelerating expansion(dark energy)? From the observation of 1998, we found that our universe has been continuing accelerating expansion, and the unknown cause for this ...
2k views

### Does Quantum Physics really suggests this universe as a computer simulation? [closed]

I was reading about interesting article here which suggests that our universe is a big computer simulation and the proof of it is a Quantum Physics. I know quantum physics tries to provide some ...
2k views

### Do radio waves go faster than the speed of light? [closed]

My science teacher used to say a lot of weird stuff, but I'm just making sure on this one.
172 views

### Does one second exist? [closed]

Let us assume .5 second has passed. Now similarly let .9 seconds also passed.. Then let's say that .99 second has passed...we're still not done because 1 second hasn't passed. Then follows .999 ...
730 views

### Violation of Newton's Second Law (?) [closed]

Here the big circle denotes the circular path of a stone (small circle on path) tied to a string from the centre of the circular path. This is COMPLETELY HORIZONTAL At an instant the velocity in ...
1k views

### Should linear algebra and vector calculus from traditional courses be replaced with geometric algebra? [closed]

geometric algebra gives geometric meaning to linear algebra and much more. it can provide a coordinate free geometric interpretation of spaces. those who learn of ...
405 views

### Entanglement, really? [duplicate]

If I have two "entangled" particles and I know the spin state of every one of them. Then, I change the spin state of one of the particles, will it affect the spin state of the other particle even if ...
149 views

### Street Light Interference Phenomenon [closed]

Is there a scientific approach that can explain the street light interference phenomenon? Everytime I walk past a Streetlight it turns off.
140 views

### How do I publish a physical constant [closed]

I think what i've found is a physical constant that is a physical quantity, universal in nature and constant in time. but It contrasted with a mathematical constant, which is a fixed mathematical ...
203 views

### $E=mc^2$ why is it $c^2$ and not just $c$?

Why is constant for the conversion of mass to energy square of the ligths speed? is it bedside it's the fastest real matter?
195 views

### Do events exist after our death if we can't measure them? [closed]

The great physicist Raphael Bousso predicted time will end in this article. We can't measure anything after our death in principle. So, does time end when we die?
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### About how much force would something have to exert to be effectively unstoppable? [closed]

Assuming an object is moving in a straight line propelled by a force. How much energy would that force have to exert so that there are no known forces or objects that could stop it from moving in that ...
11k views

### Is Athene's Theory of Everything a respectable theory? [closed]

Athene's Theory of Everything is a very popular youtube video proposing a "theory of everything": How respectable is this video? Is it complete hogwash, or is there an element of truth to it? Can ...
346 views

### Could a bubble of photons make a spaceship massless? [on hold]

I'm not sure how theoretically possible this is but my question is... If we could somehow make a perfect bubble of photons (a massless bubble) and put a spaceship inside it, could it therefore ...
52 views

### Temperature limit of the increase in heat

If the sun is the hottest known thing to humans is it possible to have a temperature greater than the sun?
97 views

### What is an $n$ dimensional space? [closed]

How an $n$ dimensional space looks like? Is it possible that we are really in a space of dimension greater than 3?
716 views

### How can Young's modulus be dimensionless, but still have units? [closed]

According to this wikipedia entry: Young's modulus is the ratio of stress, which has units of pressure, to strain, which is dimensionless; therefore, Young's modulus has units of pressure. From ...
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