How does velocity affect a rocket?

The greater the exhaust velocity of the gases, the greater the acceleration. The faster the rocket burns its fuel, the greater its acceleration. The smaller the rocket’s mass, the greater the acceleration.

How does thrust relate to velocity?

The force (thrust) is equal to the exit mass flow rate times the exit velocity minus the free stream mass flow rate times the free stream velocity. As long as the exit velocity is greater than the free stream (entrance) velocity, a high engine airflow will produce high thrust.

What is exit velocity of rocket?

Some typical values of the exhaust gas velocity ve for rocket engines burning various propellants are: 1.7 to 2.9 km/s (3800 to 6500 mi/h) for liquid monopropellants. 2.9 to 4.5 km/s (6500 to 10100 mi/h) for liquid bipropellants. 2.1 to 3.2 km/s (4700 to 7200 mi/h) for solid propellants.

What does rocket thrust depend on?

Thrust is produced according to Newton’s third law of motion. The amount of thrust produced by the rocket depends on the mass flow rate through the engine, the exit velocity of the exhaust, and the pressure at the nozzle exit.

Why does a rocket keep moving upwards even after the thrust has finished?

A rocket launches when the force of thrust pushing it upwards is greater than the weight force due to gravity downwards. This unbalanced force causes a rocket to accelerate upwards. A rocket will continue to speed up as long as there is a resultant force upwards caused by the thrust of the rocket engine.

How does the velocity of the rocket change as the rocket moves upwards?

Rockets. At lift-off, hot burning gas is pushed downwards by the rocket motors. The hot gas pushes back on the rocket in an upwards direction. When this upwards push, or thrust, exceeds the weight of the rocket, the forces acting on the rocket are unbalanced and the rocket accelerates upwards.

Why do rocket nozzles expand?

The basic idea is to lower the pressure of the exhaust by expanding it in the nozzle, until it reaches ambient air pressure at the exit. The expanding nozzle addresses this to a degree by including two skirts on a single engine, one inside the other.

How does a de Laval nozzle work?

The gas flow through a de Laval nozzle is isentropic (gas entropy is nearly constant). As the gas exits the throat the increase in area allows for it to undergo a Joule-Thompson expansion wherein the gas expands at supersonic speeds from high to low pressure pushing the velocity of the mass flow beyond sonic speed.

How does gravity affect a rocket?

A rocket launches when the force of thrust pushing it upwards is greater than the weight force due to gravity downwards. This unbalanced force causes a rocket to accelerate upwards.