Difference between revisions of "Talk:Thrust-to-weight ratio"

Revision as of 17:43, 1 November 2013

Slowing down with a TWR below 1?

How are you able to slow down with a TWR below 1? A TWR below 1 basically says, that the thrust is lower than the weight and this means that there is still a remaining force pulling the craft down. And instead of slowing it down it should accelerate such craft. It only reduces the acceleration, but you will still get faster, and considering that most parts break at relatively low impact speeds it won't help much. I would say the main reason to thrust is to loose mass (and therefore weight). — xZise [talk] 17:08, 6 October 2013 (CDT)

Crap, I suppose that it would only be useful if you had like a TWR .99 and fired full blast before you started free falling. Even if you had those conditions and did that, you would soon burn enough fuel to get a TWR > 1. I suppose that it's not really practical then. I'll edit it out. Zombie Elvis (talk) 18:29, 6 October 2013 (CDT)

Acceleration

I think the acceleration formula is not correct. It should be:

${\displaystyle a={\frac {F_{T}-F_{G}}{m}}={\frac {F_{T}-mg}{m}}={\frac {F_{T}}{m}}-g=g({\text{TWR}}-1)}$

But of course this is just the acceleration at t=0, when the fuel burns it increases. To get an accurate formula which describes acceleration over time we would have to solve a differential equation...

Please correct me if I'm wrong. --FauleSocke (talk) 12:43, 1 November 2013 (CDT)