A uniform rod rotates in a horizontal plane about a
verticalaxis through one end. The rod is 6.00 m long, weighs 10.0
N, androtates at 240 rev/min clockwise when seen from
above.Calculate
a.) the rotational inertia of the rod about the axis
ofrotation and
b.) the angular momentum of the rod about that axis.

Respuesta :

Answer

given,

length of rod (L)= 6 m

weight of the rod (W)= 10 N

rotates at = 240 rev/min

                = [tex]240\times \dfrac{2\pi}{60}[/tex]

                = 25.13 rad/s

a)  Rotational inertia of the rod about axis of rotation

[tex]I = I_{CM} + m d^2[/tex]

d is the distance from the center of gravity.

  d = L/2

[tex]I = \dfrac{1}{2}mL^2+ m (\dfrac{L}{2})^2[/tex]

[tex]I = \dfrac{3}{4}mL^2[/tex]

[tex]I = \dfrac{3}{4}\times \dfrac{10}{9.8}\times 6^2[/tex]

  I = 27.55 kg.m²

rotational moment of inertia of the rod is equal to I = 27.55 kg.m²

b)angular momentum of rod

   L = I ω

   L =27.55 x 25.13

   L = 692.36 Kg.m²/s

angular momentum of rod is equal to L = 692.36 Kg.m²/s