ilovephysics
Nov25-05, 12:17 AM
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, im not quite sure if frequency or amplitude is easier to change, im guessing frequency because amplitude cannot be directly changed, whereas frequency you just move the string up and down faster?
anyways to the question im 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 dont 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 im 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 dont 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?