As a rocket ascends, its acceleration increases even though the net force on it stays constant. why? (assume a traveling distance small enough that the thrust, acceleration due to gravity and atmosphere do not change. the faster a rocket moves the more acceleration is imparted to it from a given force. as a rocket ascends it's momentum increases with it's speed. the greater the momentum of the rocket, the greater the acceleration imparted to it from a given force. as the rocket ascends, fuel is burned at a faster rate resulting in a larger acceleration. the rocket's mass decreases as its fuel is consumed. the same net force acting on a smaller mass results in a larger acceleration.