To calculate the force between two negative charges, we use the formula which is given by the Coulomb`s Law as

Here,
and
are the charges on the pith balls, r is the separation between the charges and k is constant and its value is
.
Given
and
.
Substituting these values in above formula we get,

Thus, the repulsive force between two pith balls is
.
Answer:

Explanation:
let the ladder is of mass "m" and standing at an angle with the ground
So here by horizontal force balance we will have

by vertical force balance we have

now by torque balance about contact point on ground we will have

so we will have

now from first equation we have


Answer:

Explanation:
The Joule-Thomson coefficient is the ratio of the change of temperature to the change of pressure under isoenthalpic conditions:

Initial and final properties are:
. Superheated Vapor.
. Superheated Vapor.
The Joule-Thomson coefficient is approximately:


Answer:
0.83 ω
Explanation:
mass of flywheel, m = M
initial angular velocity of the flywheel, ω = ωo
mass of another flywheel, m' = M/5
radius of both the flywheels = R
let the final angular velocity of the system is ω'
Moment of inertia of the first flywheel , I = 0.5 MR²
Moment of inertia of the second flywheel, I' = 0.5 x M/5 x R² = 0.1 MR²
use the conservation of angular momentum as no external torque is applied on the system.
I x ω = ( I + I') x ω'
0.5 x MR² x ωo = (0.5 MR² + 0.1 MR²) x ω'
0.5 x MR² x ωo = 0.6 MR² x ω'
ω' = 0.83 ω
Thus, the final angular velocity of the system of flywheels is 0.83 ω.