- #1
ilovephysics
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first i have a quick question, for average power of a transverse harmonic wave the equation has the quantities tension, frequency and amplitude. the question asks me to find how much i need to change each quantity to increase the power by a factor of 100, i understand all that but then it asks me which quantity is the easiest to change. i got that the tension needed to be increased by a factor of 10000, and the frequency and amplitude only needed a factor of 10, I am not quite sure if frequency or amplitude is easier to change, I am guessing frequency because amplitude cannot be directly changed, whereas frequency you just move the string up and down faster?
anyways to the question I am having trouble with:
1) the linear mass density of a nonuniform wire under constant tension decreases gradually along the wire so that an incident wave is transmitted without reflection. The wire in uniform for -infinity < x <= 0. In this region a transverse wave has the form y(x,t) = 0.003cos(25x-50t) with x,y in meteres and t in seconds. From x = 0 to x =20m the mass density decreases from initial mass density to (initial mass density / 4). For 20<= x < infinity, the mass density is constant at (initial mass density / 4). a) what is the wave velocity for large values of x b)what is the amplitude for large values of x? c) give y(x,t) for the large values of x
i got part a and it turns out to be 4 m/s, but i don't know what to do to get the amplitude, also in part c how do i find the k and w(omega)? is the k constant?
anyways to the question I am having trouble with:
1) the linear mass density of a nonuniform wire under constant tension decreases gradually along the wire so that an incident wave is transmitted without reflection. The wire in uniform for -infinity < x <= 0. In this region a transverse wave has the form y(x,t) = 0.003cos(25x-50t) with x,y in meteres and t in seconds. From x = 0 to x =20m the mass density decreases from initial mass density to (initial mass density / 4). For 20<= x < infinity, the mass density is constant at (initial mass density / 4). a) what is the wave velocity for large values of x b)what is the amplitude for large values of x? c) give y(x,t) for the large values of x
i got part a and it turns out to be 4 m/s, but i don't know what to do to get the amplitude, also in part c how do i find the k and w(omega)? is the k constant?