Post Number: 9
|Posted on Tuesday, 22 October, 2013 - 12:18 pm: |
I have solved the first two parts of this question but I do not understand what the official solution says when it says "reversing the motion". Can anyone help? Thank you.
Post Number: 825
|Posted on Tuesday, 22 October, 2013 - 03:05 pm: |
Reversing the motion means projecting the particle from Q to P instead of from P to Q.
Post Number: 10
|Posted on Tuesday, 22 October, 2013 - 03:49 pm: |
I had understood that but could not quite see how it would work. Perhaps I was tired. Is this the only way to do it?
Post Number: 826
|Posted on Tuesday, 22 October, 2013 - 05:48 pm: |
What they seem to be doing is using the fact that the reverse motion is just another example of the same type and substituting the relevant angles into the result they'd obtained (so theta is replaced by -phi and alpha by -alpha). If I get time I'll have more of a look at this question and see if I can think of any other methods.