Answer:
c) 
Explanation:
Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:

where k is a proportionality constant with the value 
In this case
, so we have:

Solving the equation for q, we have:



Replacing the given values:


Answer:
Explanation:
This question is based on the Law of Conservation of Angular Momentum.
Angular momentum (L) equals the moment of inertia (I) times the angular speed (ω).
L = Iω
If momentum is conserved,
I₁ω₁ = I₂ω₂
Data:
I₁ = 3.5 kg·m²s⁻¹
ω₁ = 6.0 rev·s⁻¹
I₂ = 0.70 kg·m²s⁻¹
Calculation:

Option B is the correct answer.
MKS system gives the following units:
Distance ----- meters
Mass ----- Kilograms
Time ----- seconds
meter is basic unit for length measurement. smaller units are centimeter, millimeter, micrometer, bigger units are kilometer and so on.
kilogram is the basic unit for mass. smaller unit is gram.
second is the basic unit for time. Greater units are minutes, hours, smallest unit are micro second and so on.
100 meters divided by a speed of 12.5 meters a second equals 8 seconds.