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 :


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

l = r


For 6 spokes, 
So, the net moment of inertia of the wagon is :


So, the moment of inertia of the wagon wheel for rotation about its axis is
. Hence, this is the required solution.
Answer:
time required is 6.72 years
Explanation:
Given data
mass m = 3.20 ✕ 10^7 kg
height h = 2.00 km = 2 × 10^3 m
power p = 2.96 kW =2.96 × 10^3 J/s
to find out
time period
solution
we know work is mass × gravity force × height
and power is work / time
so we say that power = mass gravity force × height / time
now put all value and find time period
power = mass × gravity force × height / time
2.96 × 10^3 = 3.20 ✕ 10^7 × 9.81× 2 × 10^3 / time
time = 62.784 × 10^10 / 2.96 × 10^3
time = 21.21081081 × 10^7 sec
time = 58.91891892 × 10^3 hours
time = 6.72 years
so time required is 6.72 years
we assume the acceleration is constant. we choose the initial and final points 1.40s apart, bracketing the slowing-down process. then we have a straightforward problem about a particle under constant acceleration. the initial velocity is v xi =632mi/h=632mi/h( 1mi 1609m )( 3600s 1h )=282m/s (a) taking v xf =v xi +a x t with v xf =0 a x = t v xf −v xf = 1.40s 0−282m/s =−202m/s 2 this has a magnitude of approximately 20g (b) similarly x f −x i = 2 1 (v xi +v xf )t= 2 1 (282m/s+0)(1.40s)=198m