Answer:

Explanation:
I = Moment of inertia = 
m = Mass of two atoms = 2m = 
r = distance between axis and rotation mass
Moment of inertia of the system is given by

The distance between the atoms will be two times the distance between axis and rotation mass.

Therefore, the distance between the two atoms is 
Copper is the best material
Answer: increases
Explanation:
Because the relationship between hand d is counter
Answer:
W=561.41 J
Explanation:
Given that
m = 51 kg
μk = 0.12
θ = 36.9∘
Lets F is the force applied by man
Given that block is moving at constant speed it mans that acceleration is zero.
Horizontal force = F cos θ
Vertical force = F sinθ
Friction force Fr= μk N
N + F sinθ = m g
N = m g - F sinθ
Fr = μk (m g - F sinθ)
For equilibrium
F cos θ = μk (m g - F sinθ)
F ( cos θ +μk sinθ) = μk (m g
Now by putting the values
F ( cos 36.9∘ + 0.12 x sin36.9∘)=0.12 x 51 x 10
F= 70.2 N
We know that Work
W= F cos θ .d
W= 70.2 x cos 36.9∘ x 10
W=561.41 J