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9 views

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 ...
8 views

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 ...
22 views

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 ...
104 views

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 ...
5 views

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?
14 views

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
+50

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: ...
30 views

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 ...
116 views

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 ...
4 views

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 ...
22 views

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" ...