ATAR Notes: Forum

Archived Discussion => 2011 => Mid-year exams => Exam Discussion => Victoria => Physics => Topic started by: sam23z on June 14, 2011, 10:51:31 pm

Title: Special relativity answers?
Post by: sam23z on June 14, 2011, 10:51:31 pm
Anyone do this detailed study?
Title: Re: Special relativity answers?
Post by: yawho on June 15, 2011, 10:28:46 am
http://www.itute.com/board/viewtopic.php?f=6&t=2414
Title: Re: Special relativity answers?
Post by: Shark 774 on June 15, 2011, 03:04:46 pm
Do you guys agree with itute's answer for question 2? They said option B, but option B isn't really correct coz it's not more massive at "high speed"; it's more massive at any speed that's not zero.
Title: Re: Special relativity answers?
Post by: xZero on June 15, 2011, 03:14:28 pm
well A is wrong and so is D. In this case the most appropriate answer would be B, not saying that its the best answer ever but its the most correct out of B and C. C didn't mention the increase in mass while B did.
Title: Re: Special relativity answers?
Post by: Shark 774 on June 15, 2011, 04:39:51 pm
well A is wrong and so is D. In this case the most appropriate answer would be B, not saying that its the best answer ever but its the most correct out of B and C. C didn't mention the increase in mass while B did.
A and C are most definitely wrong. Why is D wrong?
Title: Re: Special relativity answers?
Post by: sam23z on June 15, 2011, 04:46:41 pm
Quote
A and C are most definitely wrong. Why is D wrong?

Indeed, I also had D...
Title: Re: Special relativity answers?
Post by: xZero on June 15, 2011, 05:32:44 pm
It's been a year since i last did special relativity so i might be wrong but, for D, E=gamma*m*c^2. The total energy-mass is dependent on 3 things, gamma rest mass and c^2. Saying that total mass-energy depends on gamma is not as accurate as saying it is proportional to gamma. It feels like it's saying that it only depends on gamma. Who knows maybe vcaa will give both B and D the mark
Title: Re: Special relativity answers?
Post by: Shark 774 on June 15, 2011, 06:07:23 pm
It's been a year since i last did special relativity so i might be wrong but, for D, E=gamma*m*c^2. The total energy-mass is dependent on 3 things, gamma rest mass and c^2. Saying that total mass-energy depends on gamma is not as accurate as saying it is proportional to gamma. It feels like it's saying that it only depends on gamma. Who knows maybe vcaa will give both B and D the mark

Yeah fair point I guess. I think A and C are definitely wrong and there are problems with both B and D. It's a fairly ridiculous question though really.