SciForums.com > Science > Physics & Math > Evidence against SR: Real Rocket Motion PDA View Full Version : Evidence against SR: Real Rocket Motion Post ReplyCreate New Thread martillo02-08-06, 08:02 AMThe real rocket motion equation shows that it obeys Newton´s Law of Force F=ma and not the relativistic definition F=dp/dt! Please take a look at: Real Equation of Force (http://www.geocities.com/anewlightinphysics/new_evidence/The_real_equation_of_force.htm) qwerty mob02-08-06, 08:14 AM"the force acting on the rocket is due to the expelled mass Not exactly. The lost mass is equal to the fuel burned for thrust. Check here (http://exploration.grc.nasa.gov/education/rocket/rktpow.html). Light02-08-06, 08:19 AMThe real rocket motion equation shows that it obeys Newton´s Law of Force F=ma and not the relativistic definition F=dp/dt! Please take a look at: Rocket Motion Force and Momentum (http://www.geocities.com/anewlightinphysics/new_evidence/Rocket_Motion_and_Momentum.htm) Well, whoop-de-do! Have you even paused to think that it might be because no rocket can go fast enough to introduce ANY relativistic effects???? :bugeye: Zephyr02-08-06, 01:07 PMThe real rocket motion equation shows that it obeys Newton´s Law of Force F=ma and not the relativistic definition F=dp/dt! Rockets don't change mass because of relativity, they change mass because of the heck of a lot of fuel they expel every second! Much as I look forward to the time we have rockets near lightspeed, it hasn't happened yet... martillo02-08-06, 01:14 PMZephir is right. dp/dt = m(dv/dt) + (dm/dt)v and if F=dp/dt the second term is considerable since the variation of the mass with velocity is considerable. Post ReplyCreate New Thread