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What are the uses of the optative mood, and how would you identify its meaning in context?

The optative mood is more remote than the subjunctive, and only exists in Greek and a handful of other languages, so I think it’s useful to have students identify it and know how best to express it in tra...

Answered by Flavia E. • Classical Greek tutor

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Two satellites are in orbit around the Earth. The first is in a geostationary orbit, the second satellite at radius half that of the first. What is the (approximate) period, in hours, of the second satellite?

A geostationary satellite is one that remains above the same location on Earth. This means it has to be above the equator, and its orbit period is exactly 24 hours! The period of a circular orbit is dista...

Answered by Hubert A. • PAT tutor

6625 Views

Derive an expression for the centripetal acceleration of a body in uniform circular motion.

(I assume familiarity with positions represented by vectors and differentiation of trigonometric functions). Consider the coordinates of a point moving in a circle of radius r around the origin. The equat...

Answered by Hubert A. • Physics tutor

3546 Views

Explain the functional differences between a t-RNA and an m-RNA molecule

A tRNA molecule is one which carries an amino-acid and takes it to ribosomes to be inserted into an amino-acid sequence making a protein during the translation step of protein synthesis. An mRNA molecule ...

Answered by Chintan P. • Biology tutor

2356 Views

The equation of a circle is x^2-6x+y^2+4y=12. Complete the square to find the centre and radius of the circle.

When we complete the square, we're looking for an equation that looks like (x-a)² + (y-b)² = r², where (a,b) is the centre and r is the radius. When we expand brackets usi...

Answered by Hubert A. • Maths tutor

4195 Views