20 kg and whose radius is You are designing a lathe motor, part of which consist
ID: 2040295 • Letter: 2
Question
20 kg and whose radius is You are designing a lathe motor, part of which consists of a uniform cylinder whose mass is 1 0.50 m that is mounted so that it turns without friction on its axis, which is fixed. The cylinder is driven by a belt around its perimeter and exerts a constant torque. At t - 0, the cylinder's angular velocity is zero. At t 25 s, i speed is 550 rev/min. (a) What is the magnitude of the cylinder's angular momentum att25 s? kg-m2/s (b) At what rate is the angular momentum increasing? kg m2/s (c) What is the magnitude of the torque acting on the cylinder? N m (d) What is the magnitude of the frictional force acting on the rim of the cylinder?Explanation / Answer
a) L = (1/2 M R2) w
= 1/2 * 120 * 0.50 * (550 * 2 pi / 60)
= 864 kg.m2/s
b) dL / dt = 864 / 25
= 34.56 kg.m2/s
c) magnitude of torque = 34.56 N.m
d) F = torque / r = 34.56 / 0.50
frictional force = 69.12 N
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.