Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Five objects of equal mass are shown below together with the axis about which th

ID: 1976175 • Letter: F

Question

Five objects of equal mass are shown below together with the axis about which they are rotating. Select from the pull-down menus the objects in order of increasing rotational energy, with 1 having the smallest rotational energy and 5 having the highest rotational energy.

a) Solid Cylinder, about cylinder axis with R = 3 m and gw = 4 rad/s.

b) Thin Spherical shell, about any diameter, with R = 3 m and gw = 4 rad/s.

c) Thin rod, about axis through center, perpendicular to the length with l = 9 m and gw = 4 rad/s.

d) Thin cylindrical shell, about cylinder axis with R = 2 m and gw = 5 rad/s.

e) Solid Sphere, about any diameter, with R = 4 m and gw = 4 rad/s.

Explanation / Answer

a) K1 = (1/2)I2

K1 = (1/2)(mr2/2)2

K1 = (1/2)(m)(9)(4)2/2

K1 = 36m

b) K2 =(1/2)(2/3)m(3)242

K2 = 48m

c) K3 = 0

d) K4 = (1/2)mr2(5)2

K4 = 50m

e) K5 = (1/2)(2/5)mr2 2

K5 = 51.2m

hence, K5 > K4 > K2 > K1 > K3