The correct answer is “C” ultrasound. Hope this helps!
let the distance of pillar is "r" from one end of the slab
So here net torque must be balance with respect to pillar to be in balanced state
So here we will have

here we know that
mg = 19600 N
Mg = 400,000 N
L = 20 m
from above equation we have



so pillar is at distance 10.098 m from one end of the slab
No it won't. It'll vary inversely as the square of the separation.
Answer:
a)
b)
c) 0 J/K
d)S= 61.53 J/K
Explanation:
Given that
T₁ = 745 K
T₂ = 101 K
Q= 7190 J
a)
The entropy change of reservoir 745 K

Negative sign because heat is leaving.

b)
The entropy change of reservoir 101 K


c)
The entropy change of the rod will be zero.
d)
The entropy change of the system
S= S₁ + S₂
S = 71.18 - 9.65 J/K
S= 61.53 J/K