A cardboard flag of width W is taped to the edge of a disk of radius R.
A cardboard flag of width W is taped to the edge of a disk of radius R. What angle, △θ, is subtended by the flag? Give your answer in radians, expressed in terms of W and R.
△θ= 2 sin^-1(W/2R)
If it tkes a time △t for the flag to pass through a photagate, what is the flag's (average) speed during the interval?
v = R*dtheta/dt
What is the angular speed, w, of the disk during the same interval?
w = V/R
How is v related to w?
v = Rw
If a flag of width 3.0 cm on a disk of diameter 30 cm takes 0.600 s to pass through a photogate, what is w durith this short interval?
w =
On the next revolution the flag takes 0.400 s to pass through the photogate. Estimate the angular acceleratio of the disk. What assumptions or approximations do you make?
αav =
The disk rotates due to a small mass, m, hanging at the end of a string. In one revolution, how far does the mass fall?
△y =
If the disk is speeding up as the mass falls, which is true about the magnitude of the tension in the string?
T = mg, T>mg, T<mg, T=0
How is the speed of the mass related to w of the disk?
vm =
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A cardboard flag of width W is taped to the edge of a disk of radius R.
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