# Tutor profile: Tim M.

## Questions

### Subject: Physics (Newtonian Mechanics)

Describe the third law of Newton and explain it on the example from Aeronautics.

Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. Rocket propulsion is a good example of the law: exhaust flow pushed backward generates equal force, pushing the rocket forward.

### Subject: Russian

Обьясните склонения имён существительных на примере слова "СТУЛ" в двух различных падежах.

Слово стул в предложении "Тим сидит на стулЕ" имеет окончание "Е" по правилу склонения предложного падежа. Слово стул в предложении "Тим ударил стулОМ Тома" имее окончание "ОМ" по правилу склонения творительного падежа.

### Subject: MATLAB

Given two vectors: Weight = [ 1 2 1 4 2]; Grade = [90 80 50 70 95]; Change the below loop implementation of "Weighted Average Calculation" to a more effective Matlab implementation: SumW = 0; SumWX = 0; for i=1:1:length(Weight) SumW = SumW + Weight(i); SumWX = SumWX + Weight(i) * Grade(i); end WMean = SumWX/SumW;

Effective implementation uses the Matlab ability of vector multiplication and built-in sum function: WMean = (Weight * Grade')/sum(Weight);

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