Posted by tom on .
Model rocket engines are sized by thrust, thrust duration, and total impulse, among other characteristics. A size C5 model rocket engine has an average thrust of 5.26 N, a fuel mass of 12.7 g, and an initial mass of 25.5 g. The duration of its burn is 1.90 s.
(a) What is the average exhaust speed of the engine?
(b) If this engine is placed in a rocket body of mass 57.5 g, and if the rocket is fired in outer space, what is the final velocity of the rocket? Assume the fuel burns at a constant rate
for average speed i did fthrust=change of M/change in T i got .78 this is not right help please

physics 
bobpursley,
What units are you using.
Mass change is .0127kg,
force =5.26N
deltTime=1.90sec.
v=F(time)/masschange