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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

6448 Views

a boat is in a still lake with its anchor up in the boat, it then drops its anchor till it hits the bottom of the lake. Is the water level highest a) when the anchor is in the water. b) when the anchor is in the boat. c) it makes no difference.

b) when the anchor is in the lake it displaces the amount of water equivallent to the volume of the anchor, when the anchor is in the boat it displaces the amount of water equivallent to the anchors mass....

Answered by Benjamin C. • PAT tutor

1404 Views

If water is trapped between two planes on a train, and the train decelerates at 4ms^-2. What angle does the surface of the water make with the horizontal?

Draw a diagram of forces on a single particle at surface of water.

Water is stationary in reference to train, thus when including decelerating force, resulting force is zero.

Balance horrizo...

Answered by Oliver S. • PAT tutor

1638 Views

How many trailing zeros are there in 100! (100 factorial)?

We will answer this by considering the numbers which contribute towards trailing zeros and by calculating how many such numbers there are within 100!. The solution should enlighten the student on the use ...

Answered by Waseem A. • PAT tutor

2040 Views

How do I evaluate something like 3070^2-3069^2?

This looks pretty daunting, but the key to this sort of a problem, which has come up a couple of times in previous PAT tests, is to recognise that this expression is actually the difference of two squa...

Answered by Sam C. • PAT tutor

2616 Views