Map sapling learning A child\'s top is held in place, upright on a frictionless
ID: 1475484 • Letter: M
Question
Map sapling learning A child's top is held in place, upright on a frictionless surface. The axle has a radius of r 2.46 mm. Two strings are wrapped around the axle, and the top is set spinning by applying 1.65 N of constant tension to each string. If it takes 0.770 s for the string to unwind, how much angular momentum does the top acquire? Assume that the strings do not slip as the tension is applied. Number If the final tangential speed of point P h 27.0 mm above the is 1.25 m/s and the angle 6 is 29.0°, what is the top's moment of inertia? Number Top View: kg m A O Previous Check Answer Next Ext HintExplanation / Answer
dL/dt = t(torque)
L(t) = L(0) + T(t)
L(t) = 2F*r*t
L = 2 * 1.65 * 2.46 10^-3 * 0.770
L = 6.25 x 10^-3 kg .m^2/s
part b )
h = r cos(theta), so r = h/cos(theta)
Furthermore,
v = wr
w = v/r = v / (h/cos(theta)) = v cos(theta)/h
L = I*w
I = L/w = L*h /( vcos(theta) )
I = 6.25 x 10^-3 * 27 x 10^-3 / ( 1.25 x cos 29)
I = 1.54 x 10^-4 kg .m^2