# Couple of hard physics questions

1. Sep 30, 2009

### greener1993

1. How can something travel faster than light?

2. You have two identical bars of iron – except that one is a magnet. Without using any piece of apparatus, or any other object, how can you find out which is which?

Hope you can help

Thankyou :)

2. Sep 30, 2009

### cdubsean

As to your first question http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html" [Broken] this explains many ways you can.

question 2 ) good luck! :)

Last edited by a moderator: May 4, 2017
3. Sep 30, 2009

### Staff: Mentor

What do you think? Show what you've done so far.

4. Sep 30, 2009

### greener1993

Not a clue for question 2. Been thinking for 3 weeks on this (3 week homework) and still have no idea. Of course i have ideas with using appratus but i don't have a clue without appratus.

with question 1 cdubsean gave me that nice website that i need to look at in detail. But yet again i just have no clue what its all about.

Theses questions came from a set of 10. told they were A level. managed to work out most of them but just cant seem to swing my head around theses ones

5. Oct 2, 2009

### Staff: Mentor

If you had a bar of unmagnetized iron and a identical looking bar magnet, what could you do with them? Be creative!

6. Oct 2, 2009

### greener1993

hey doc al saw what you wrote on my other topic.... giving me the answer is completly useless. ofcourse.

This is a 3 - 4 weeks homework with about 20 questions on it, ive done all but 1... this one ofc. Been thinking about it the second i got the paper. iv put plenty of thought into it.

Unfortanlly i don't have a clue on hte question, just starting AS physics and the cretivness needed and the understanding given in my 12 lesson is not at the right level at the moment.

Maybe you can give me a clue to get me starting thinking on the correct lines.

7. Oct 2, 2009

### Staff: Mentor

Hint: Where is the magnetic field of a bar magnet greatest?

8. Oct 2, 2009

### greener1993

The magnets are strongest on both sides (poles) what im thinking of is there is no magnetic feild in the middle of theses 2 poles. Calling magets 1 and 2 i would try the center of bar 1 against the end of bar 2. then see if there is a force. lets say there is a force in this one so bar 2 would be the magnet. If we used the end of bar 1 on the center of bar 2 we would expect to see no force and therefor the poles on bar 1 are not magnetic.

Just an idea.... correct? on the right lines? or miles off?