denis

I re-stringed my guitar, and i hear my string "cracking" when I bend it, but only at high bends like 2 step, 2 and a half step bends... I've read somewhere that people "stretch" the strings before tuning them when they restring their guitar? Is there a way to break in new strings so they dont snap right away...

Show that |z|^n = |z^n| for some complex number z.

Help

lim (x,y,z)->(0,0,0) 2xz/(x²+y²+z²) = 0

I don't even know how to start

Out of no where, what I think is my fan is making this loud unbearable noise... This has never happened before, my laptop doesn't seem to be overheating or anything. I also noticed that typing the letter "a" changes the intensity of the sound, if I hold "a" for several seconds the noise is reduced for some reason.. Help?

I ve been playing guitar for a couple of months now, and I ve been getting into lots of solos lately. The annoying problem I m having is with string bending. It s not difficult to do, but when I do quick bends I end up strumming one or two extra strings by accident...

For example, If i m bending the B string, I ll strum the D or G or sometimes both! Is there a specific technique for string bending?

If a plane (say a boeing) were to fly tangent to some point on Earth into space, how much power would it need?

What would be the required speed, acceleration, energy, thrust, lift, etc (the more the better!)

I'm expecting the overall power to decrease as the plane gets farther from Earth (as the gravitational pull will decrease with distance) but I'd like to know how much it would need to cross the Karman line?

Thanks!

I'm reading a book on quantum mechanics titled "Quantum Mechanics: The Theoretical Minimum" by Leonard Susskind (if that's any help) I'm reading about quantum states and spin.. the author derives a 2x2 operator

σ_n = {(cosθ,sinθ),(sinθ,-cosθ)} this is supposed to be a matrix with entries

a11: cosθ

a12: sinθ

a21: sinθ

a22: -cosθ

and he asks the reader to find its eigenvalues and corresponding eigenvectors. I've manages to find the eigenvalues (λ=+1 and λ=-1) obvious result for spin. The author hints the reader to use an arbitrary column eigenvector

|A> = (cosα,sinα)

and solve for α in terms of θ to find the eigenvectors. Somehow, the answer is the book is

λ=+1

( cos(½θ) , sin(½θ) )

and

λ=-1

( -sin(½θ) , cos(½θ) )

I don't know how he arrives to these results. Even wolfram alpha gives different eigenvectors for eigenvalues +1 and -1:

λ=+1

(cotθ - 1 , 1)

and

λ=-1

(cotθ + 1 , 1)

here's the problem, suppose A is a square matrix and

A = kA^T where k≠±1

show that A =0.

my solution:

(kA^T)^T = kA

therefore;

kA = A

A(k-1)=0

since k cannot be ±1, A has to be zero so

A = 0

is this correct?

Let's say we have 2 identical cylinders with the same dimensions,radius,etc... one of them is solid while the other is hollow. If I were to fill the hollow one with water or some other liquid so that its mass will be the same as the solid cylinder (the water is completely still inside and doesn't move) will both cylinders have the same moment of inertia?

Infinite Σsin(14/n) diverges, so does Σsin(14/(n+1))... how come

infinite Σsin(14/n) - sin(14/(n+1)) = sin14?

Can anybody derive this equation for me?

m = mo/sqrt(1-v^2/c^2)

Whenever I try i get to the conclusion that the mass of the object in motion is equal to the rest mass, I think i'm missing something, any help Would be appreciated thanks

It's been bugging me, i've been trying to update some apps and all it does is download, then says updating or installing for ages and when i go back to the google store its like nothing ever happened And i have to start over. I have a samsung galaxy s4 anybody know whats going on?

In a spring block system the mass of the block is 0.2kg and k=5N/m. The spring compresses by 6cm at time t=π/10s and has a velocity of -40cm/s. Find the equation of the displacement

I have trouble finding the phase angle.

Imagine this spring block system resting horizontally, it oscillates left and right... when is the velocity negative? Is it when it the block travels from the right max displacement to the equilibrium point

OR

when it travels from right max displacement to left max displacement? Im confused when trying to find the phase angle in the unit circle...

for instance the problem says the block has mass 0.2kg with k= 5N/m and at time π/10s it compresses by 6cm and has velocity of -40cm/s... how do i choose the correct phase angle

I dont seem to understand whats the max equip load you can have before starting to fat roll. People say its 50% of your current equip load but when i check mine, it says 12/60 and i still fat roll, thats like only 20%

A block of mass 0.25 kg can slide over a frictionless horizontal surface. It is attached to a spring whose stiffness constant is k = 16 N/m. The block is pulled 49 cm and let go.

At what position is the kinetic energy equal to the potential energy?

I have absolutely no idea how to interpret this question, my mind is just going blank, I would appreciate some clarification

I'm starting to get interested in the theory of relativity and would definitely love to understand more, does anybody have a good book to recommend me? (Cegep science student)

I keep hearing "first semester almost over" and i'm like you mean the first term right? They keep saying no second semester starts after the holidays blah blah but a semester is a year divided into 2 terms... can someone fill me in on this please

A block of mass 0.25 kg can slide over a frictionless horizontal surface. It is attached to a spring whose stiffness constant is k = 16 N/m. The block is pulled 49 cm and let go.

A) at what position is the kinetic energy equal to the potential energy?

I dont know how to interpret this question

I dont want any solutions, i just want to know how i can find the position of an object attached to a spring when the kinetic energy is equal to the potential energy? How would you set up an equation?