Exam Preparation: Tips for Success and a Helpful Practice Question

[versaknight]

well i have an exam on mon so i ahve been practicing I am not very sure how to do this qn . this seems easy but i want to make sure any help would be greatly appecitated .ITs a pcture[PLAIN]http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc6/216457_217324648278600_100000032007600_930824_4465603_n.jpg

 

[JesseM]

well i have an exam on mon so i ahve been practicing I am not very sure how to do this qn . this seems easy but i want to make sure any help would be greatly appecitated .ITs a pcture[PLAIN]http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc6/216457_217324648278600_100000032007600_930824_4465603_n.jpg[/QUOTE]
Do you have any thoughts on how to approach the problems, so you could give your ideas and people could comment rather than just giving the answers? Are you familiar with the equations for length contraction and time dilation?

 

[versaknight]

yes what i did was calculate the reltive velcocity of the orion rocket with respect to the crew of sirius and i used this velcity to find the contracted length iss that correct

 

[JesseM]

yes what i did was calculate the reltive velcocity of the orion rocket with respect to the crew of sirius and i used this velcity to find the contracted length iss that correct

Yes, that's the right approach for question (i).

 

[versaknight]

for part 2 is it just contracted length divided by relative velocity and how do i approach part 3?

 

[eczeno]

think about how the situation would look from each point of view. is there a difference?

 

[versaknight]

well i don't think so beacuse for orion , sirius will be moving at the same relative speed away from him. since they have the same length, the contracted length will be the same and the time taken will be the same.. that's what i think

 

[ideasrule]

well i don't think so beacuse for orion , sirius will be moving at the same relative speed away from him. since they have the same length, the contracted length will be the same and the time taken will be the same.. that's what i think

That's correct. Next time, it's probably easier to post your attempts along with the question, so that we can easily check to see whether you've already gotten the right answers.

 

[eczeno]

right. if they were different, then we would have just done an experiment that distinguished one inertial frame from the other!

by the way, in part two, you need to account for the lengths of both ships, but only one is contracted. do you see why?

 

[versaknight]

yes i get it . thanks