Answer;
-A model
Explanation;
-A mathematical model is an abstract model that uses mathematical language to describe the behavior of a system. A Mathematical Model tries to copy how a real world thing works using equations.
-Usually a mathematical model describes a system by a set of variables and a set of equations that establish relationships between the variables. Variables may be of many types; real or integer numbers, for example.
-The Area A of a circle with radius r is given by the formula A = πr2. In this formula π ≈ 3.1416... is a number which is a constant, and A and r are variables or unknowns. A is called the subject of the formula.
For the answer to the question above,
we can get the number of fringes by dividing (delta t) by the period of the light (Which is λ/c).
fringe = (delta t) / (λ/c)
We can find (delta t) with the equation:
delta t = [v^2(L1+L2)]/c^3
Derivation of this formula can be found in your physics text book. From here we find (delta t):
600,000^2 x (11+11) / [(3x10^8)^3] = 2.93x10^-13
2.93x10^-13/ (589x10^-9 / 3x10^8) = 149 fringes
This answer is correct but may seem large. That is because of your point of reference with the ether which is usually at rest with respect to the sun, making v = 3km/s.
Answer:
The true weight of the aluminium is
4.5021 kg
Explanation:
Given data
= 4.5 kg
= 1.29 
= 2.7× 
The true mass of the aluminium is given by

Put all the values in above equation we get

4.5021 kg
Therefore the true weight of the aluminium is
4.5021 kg