An anemometer for measuring wind speed consists of four metal cups, each of mass m = 104 g, mounted on the ends of four essentially massless rods of length R= 0.3 m. The rods are at right angles to each other and the structure rigidly rotates at f = 12 rev/s. Treat the cups as point masses. What is the angular momentum of the anemometer about the rotation axis? I already figured out I is 37.44 but now I'm stuck anybody now what L is?
2007-10-28 20:33:32 · 2 answers · asked by c_me_run2005 2 in Science & Mathematics ➔ Physics
The angular momentum is I*w, where I = moment of inertia and w = angular velocity in radians per second. One rev is 2π radians, so w = 24π rad/sec. Now you can calculate the angular momentum.
2007-10-28 20:55:58 · answer #1 · answered by gp4rts 7 · 0⤊ 0⤋
once you get I, the moment of inertia, you can use the equation L= I w, where w is the angular speed. u need to be sure that the I you obtained has to be the total moment of inertia. now change the frequency f to rad/s using
f = 12 rev/s*2Pi rad/rev = 24 Pi rad/s. then find w using w = 2Pir/f . finally use the equation L = Iw.
NOTE: be sure the 12 rev/s u given is not the w.
2007-10-29 03:54:00 · answer #2 · answered by Beku 1 · 0⤊ 0⤋