Answer:
r= 98.3 mm
Explanation:
For rim
R= 0.209 m
M= 4.32 kg
For rods
m= 7.37 kg
L= 2 R= 2 x 0.209 = 0.418 m
The Total moment of inertia of the wagon
I=MR²+2 x 1/12 m L²
Now by putting the values

I=0.413 kg.m²
For disk:
t= 0.0462 m
Density ρ = 5990 kg/m³
Lets take r is the radius of disk
So the mass of the disc
m'=ρ πr² t
The moment of inertia of disc
I'=1/2 m'r²
I'=1/2 x r² x ρ πr² t
Given that
I = I'
1/2 x r² x ρ πr² t = 0.413 kg.m²
1/2 x r³ x ρ π t = 0.413
r³ x ρ π t = 0.826

r³=0.00095
r=0.0983 m
r= 98.3 mm
Answer:
1. Potential hazard
2. Mining opportunity
Explanation:
The two reason, why astronomers are so interested in the discovery of additional Earth-approaching asteroids:
1. Potential hazard: We have proof that the dinosaurs got extinct because of an asteroid/comet strike on Earth. Also we have seen the effects of the Tunguska event and Chelyabinsk tragedy. These are enough to show us that asteroids can be very dangerous and wipe out the life from Earth.
2. Mining Opportunity: We have discovered a lot of asteroids which contains a lot of metal and precious elements. There can be a possibility of mining such asteroids in the future and reducing the burden on Earth.
I think it should be option (b)
Answer:
The centre of the earth is harder to study than the centre of the sun." Temperatures in the lower mantle the reach around 3,000-3,500 degrees Celsius and the barometer reads about 125 gigapascals, about one and a quarter million times atmospheric pressure.
Explanation: