Question

A 0.5 m diameter wagon wheel consists of a thin rim having a mass of 7 kg and six spokes, each with a mass of 1.2 kg. 1.2 kg 7 kg 0.5 m Find the moment of inertia of the wagon wheel for rotation about its axis. Answer in units of kg · m2 .

Answer 1

Step-by-step explanation:

It is given that,

Mass of the rim of wheel, m₁ = 7 kg

Mass of one spoke, m₂ = 1.2 kg

Diameter of the wagon, d = 0.5 m

Radius of the wagon, r = 0.25 m

Let I is the the moment of inertia of the wagon wheel for rotation about its axis.

We know that the moment of inertia of the ring is given by :

`I_1=m_1r^2`

`I_1=7* (0.25)^2=0.437\ kgm^2`

The moment of inertia of the rod about one end is given by :

`I_2=(m_2l^2)/(3)`

l = r

`I_2=(m_2r^2)/(3)`

`I_2=(1.2* (0.25)^2)/(3)=0.025\ kgm^2`

For 6 spokes,
`I_2=0.025* 6=0.15\ kgm^2`

So, the net moment of inertia of the wagon is :

`I=I_1+I_2`

`I=0.437+0.15=0.587\ kgm^2`

So, the moment of inertia of the wagon wheel for rotation about its axis is
`0.587\ kgm^2`. Hence, this is the required solution.