Week 4

You should complete the lunar phases worksheet (link on the page here) prior to the test as I've suggested.  If not then, you should hand it in at the start of class on Thursday.  You have mastering astronomy assignment 4 to be working on.

Test comments. ---last weeks post has a good start on a topics list.

Some additional comments.   I've been asked for some review problem ideas for the numerical problems.

1)    Be able to calculate the orbital speeds of a planet or moon given the data table information in the back of your books.   Try this for several planets.  Give answers in units of m/s.   When you give answers you MUST GIVE IN THE FOLLOWING FORM----EXAMPLE FOR SPEED HERE.

v=( number)  and then units.    Like     v=213 m/s

2)    How much time does it take for light to reach a given planet or travel a given distance.  You may need to use data table again.   Know where to find relevant information.

Do this for say the distance from the sun to any planet.  Try it for at least three planets.  Start with an equation in symbols (POINTS OFF FOR NOT STARTING WITH THIS STATEMENT---SHOWING WORK).

Solve for time.   In symbols.

Plug in numbers, and give result       t=________s  

Get the units correct

3)    Universal Law of gravitation.  As discussed in class and lab.  Be able to take a given force say an object is pulled on by the moon with 200N of force at 4000km from the center.  What will the force be at twice the distance, five times the distance, ten times the distance, or one half the distance.

F(new) = _____________N

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In all numerical problems you are expected to show your work.  Usually this is a few lines at most.   YOU SHOULD START WITH A PHYSICS EQUATION (OFTEN GIVEN).  YOU SHOULD RE-ARRANGE IN SYMBOLS.  YOU SHOULD PLUG IN NUMBERS.  THEN GIVE YOUR ANSWER IN THE FORM DESCRIBED ABOVE.

Following these suggestions is important for your earning the most credit on problems.