Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [physics]

Questions on the mathematics required to solve problems in physics. For questions from the field of mathematical physics use (mathematical-physics) tag instead.

This tag is for questions on the mathematics required to solve problems in physics and should not be confused with those on physics concepts. Pure physics questions should go in the Physics Stack Exchange. For questions in the field of mathematical physics, please use the tag instead.

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Clarification of the change in vector A

I understand that a change of the vector A can be the result of a rotation and a change in magnitude. (The perpendicular part and the parallel part) This can be represented by ΔA = ΔA(perpendicular) + ΔA(parallel) What I am having difficulty…
GustoCo
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Finding the ratio $\dfrac{\Delta E_X}{\Delta E_Y}$

These two cylinders are put on top. Once we heat them with an amount of $\Delta T$, the gravitational potential energy of $X$ and $Y$ are increasing by $\Delta E_X$ and $\Delta E_Y$ . Find the ratio $\dfrac{\Delta E_X}{\Delta E_Y}$ I tried to find…
Hamilton
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Simple Capacitors Circuit

I can't solve this simple circuit, made of 5 capacitors.I know i only have to use parallel and series rules. The solution in the book is $4/3$ C
tommycautero
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Find projectile Initial Velocity given max range, gravity, and height

So I've been trying to work out how to reverse a formula I found and worked on. I have thoroughly tested these formulas at desmos.com/calculator and have a realistic physics simulation playing in real-time over and over. It works EXACTLY as I need…
Anixias
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Strange factor in position time function under constant acceleration

Alternate wars says that the time taken for an object to travel a distance under constant acceleration is given by this equation: $time = 2\sqrt{\frac{distance}{acceleration}}$ For my purposes, I define two points, $\vec{x_{start}}$ and…
PrimarySecondary
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Finding the angle and velocity to hit a target in t seconds

My goal is to compute an angle + velocity combination to hit a target at point $(x,y)$ in exactly $t$ seconds. (Uniform gravity, no drag, no wind) I know that the general formula for trajectory is: $x = vt \cos \theta$, $y = vt \sin \theta -…
Wintermute
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Finding x value of Spring

An object is on a vertical spring that is currently unstretched. Using conservation of energy find how far it will stretch when it is first released? m = 100g = 0.1 kg k = 15.5 N/m The answer is supposed to be 21.5 cm = 0.215 m I first tried x =…
HeavenlyPanda
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Boyle's Law - plumbing problem turned into math problem

Browsing through some plumbing forums about pressure tanks and someone replied with this... (I should start off by mentioning it's a 40 gallon tank) "At 2.5 GPM, your 2-3 minutes of shower time between cycles is using between 5 and 7.5 gallons. If…
wesley delk
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Planck Radiation Law, and dominance of short/long wave radiation

I'm trying to show using Planck's radiation law: $$B( \lambda ) = \frac{2h c^{2} }{ \lambda^{5} } \frac{1}{\exp( \frac{hc}{ \lambda k T} - 1 )} $$ whether radiation from the Earth or the Sun dominates for a given wavelength. I'm using distance $r…
Jo Fisher
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Comparing frequency differences to period differences

I have two signals. One has a frequency of $10$ Hz, the other has a frequency of $5$ Hz. Or, in other words, one has a period of $\dfrac 1{10}$ seconds, and the other has a $\dfrac 15$ seconds. The difference in their frequencies is $10 Hz - 5 Hz…
rhombidodecahedron
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Planetary orbits in a $4$-dimensional universe

In our (presumably) $3$-dimensional universe, gravity is inversely proportional to distance squared. In a circular orbit, the force of gravity must be equal and opposite to the 'centripetal force'. $\frac {GM_1M_2}{r^2} = \frac {M_2v^2}r$. This…
Thomas Delaney
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Angular Momentum

Here is my question A particle attached to a string of length $2$ m is given an initial velocity of $6 \text {m/s}$. The string is attached to a peg and, as the particle rotates about the peg, the string winds around the peg. What length of string…
user440404
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What does 'plus or minus' mean as it pertains to real word situations?

I'm doing a lab for my AP Physics class where I have to derive an equation for velocity. Trouble is when I do I get a value for velocity that is ±. $$\pm \sqrt{g\cdot r\cdot cot(\Theta)}$$ In the past, I've ignored the + or - and just taken the +.…
Zeke Medley
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Pendulums and forming equations of motion

I have been reading up on pendulums and how to form equations of motion, there is little information available, however, I have found a source which explains and documents a double pendulum example. In the source they form the equations of motion…
this guy123
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Help! Guitarist stuck on a math(s) problem!

I'm sure this is embarrassingly basic for the folks around here, but I'm trying to rearrange this equation to give me $uw_2$ - is there anyone who could help? For the record, it's to try and help me figure out the unit weight of a string on a guitar…
cj38
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