Respuesta :
Answer:
Explanation:
Moment of inertia of wheel = 1/2 x mR² , m is mass and R is radius of wheel
= .5 x 9 x .4²
= .72 kg m²
Torque created on wheel by string = T x r , T is tension and r is radius of wheel .
13 x .4 = 5.2 N m
angular acceleration α = torque / moment of inertia
= 5.2 / .72
= 7.222 rad /s²
a ) final angular speed = α x t , α is angular acceleration , t is time.
= 7.222 x .72
= 5.2 rad /s
b )
θ = 1/2 α t² , θ is angle turned , t is time
= .5 x 7.222 x .72²
= 1.872 rad
average angular speed = θ / t
= 1.872 / .72
= 2.6 rad /s
c )
angle turned = 1.872 rad ( discussed above )
d )
length of string coming off
= angle rotated x radius of wheel
= 1.872 x .4
= .7488 m .
74.88 cm
