# All Questions

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### How to calculate the coefficient of kinetic friction using deceleration?

The original question is: A sled is pushed along a snowy road with velocity $v = 2.5\,\mathrm{m/s}$. When it is released, it glides along for $6.4\,\mathrm m$ before coming to rest. Find the ...
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### Historical meaning of action

In the Feynman lectures, it is stated Also, I should say that $S$ is not really called the ‘action’ by the most precise and pedantic people. It is called ‘Hamilton´s first principal function.’ Now ...
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### Does any force on a spring make it oscillate?

If I push one end of a spring (while the other end is attached to a rigid support) with a force of F and over a distance of $x = F/k$, it is only after a the end of the spring has been displaced x ...
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### What temperature increase results from the current 410 PPM spike in $CO_2$?

https://skepticalscience.com/skakun-co2-temp-lag.html?fbclid=IwAR2A_wvpTcWfdMjZsY_64JELzKt592FpXX8Q1UtIopgvoq3t8TqaThBGyxc So while CO2 did lag behind a small initial temperature change (which mostly ...
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### collision (elastic and inelastic)

An object A of mass 2kg is moving with a velocity of 3m/s and collides head on with an object B of mass 1kg moving in opposite direction with a velocity of 4kg . After collision they stick together. ...
111 views

### Quantization of Klein-Gordon field between two boundaries

Consider a real scalar $\phi(x,t)$ with mass $m$ in $1+1$ dimensional spacetime, described by the 2d free Klein-Gordon action. $\phi(x,t)$ lives on an interval $0 \leq x \leq L$, and is subject to ...
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### Can liquid hydrogen be ionized?

Does stripping the electrons off of hydrogen atoms affect it's boiling point in any way?
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### Difference between Displacement-time graph and Position-time graph

While going through my physics book, I got over a question which ask us to plot a position-time graph for the interval ($t=0\,\mathrm s$ to $t=5\,\mathrm s$) From the top of a tower, a ball is ...
20 views

### What is infinitesimal displacement?

This section is from the Openstax University Physics: Volume 1 online textbook. In physics, work is done on an object when energy is transferred to the object. In other words, work is done when a ...
591 views
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### How could lightning have killed 322 reindeer at one time in Norway?

Lightning is supposed to have killed 322 reindeer within an area that's about 50-80 meters in diameter on a mountain plateau in Norway. Nearly the entire herd died. Sources: (1, 2, 3, 4) Photo: ...
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### In certain conditions, does a permanent magnet loses its mass over a period of time? [on hold]

While working on an alternative cosmological paradigm of, Eigen-rotational Clusters of String-matter Universe, it was hypothesized that the fundamental matter is, Eigen-rotational elastic string-...
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### I want sites special of physical and chemical, contains some books of courses and exercices

I want sites and books to teach physics and chemistry, at the university how do I get that.?
15 views

### Higher energy of outer orbitals around nucleus

I remember reading that the outer orbitals of atom have higher energy. If an electron is given enough energy is goes to higher energy orbitals from $n=1$ to $n=2,3,4...$ My question is that why do ...
207 views

### What should be the direction of motion of a conductor in a magnetic field to produce motional emf?

Here's the textbook question: Twelve wires of equal length 'l' are connected to form a skeleton cube which moves with constant velocity v perpendicular to the magnetic field B. What will be the ...
36 views

### How can the acceleration of a person on a zipline be calculated?

I was thinking one day about how a speed, or perhaps the acceleration, of a person riding a zip line could be calculated. I first started by thinking of an ellipse where the two foci were the anchors ...
167 views

### Internal resistance and a resistor as a potential divider

Based on the fact that batteries have some kind of internal resistance, if I had a circuit that consisted of a battery and a resistor of some kind would they act like a potential (voltage) divider? ...
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### Quantum mechanics Interference

While learning wave-particle duality of an electron I found the wave with which we associate the electron is the probability wave. Now my questions are that if that is so How do electron show ...
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### Contradictory solutions to the Klein-Gordon equation as an initial value problem (canonical formulation)

I'm going to begin with a prelude about constructing the solution using the action/Lagrangian formalism in order to provide context and a point of comparison for the canonical one. The main question ...
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### Effects of positions of object in lens problemd

there was a question in which the object is place right side of a concave lens so I decided as usual like taking objects position as positive and considering the right face of the concave mirror so I ...
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### Calculating RPM of a motor

I am trying to calculate the optimal RPM of a DC motor in order to move a car. I know that the force exerted on the wheel by the motor is: $$F=9N$$ I also know the following information ("h" ...