# How does a rocket work? - R

How does a Rocket Work?
Raiden M.
2012

Isaac Newton
Isaac Newton was born on December 25, 1642 in Wools Thorpe, England. During his lifetime, he was a mathematician and a physicist. He basically created calculus and better explained the science of color and light. He was the first to explain gravity and he came up with the three basic laws of motion. One of the laws of motion is that
every action has an action and a reaction. Another is that acceleration equal mass times force. Mass is the amount of matter in an object. Acceleration can be negative or positive. Negative acceleration is speed decreasing and positive acceleration is speed increasing. The last law is that every object in motion stays in motion at a constant speed unless acted on by an outside force and every object at rest stays at rest unless acted on by an outside force. It is also explained as the law of inertia.

History of the Rocket

The first known rocket-like object was flown around 400 B.C. It was a gas propelled wooden bird made by a Greek named Archytas. Then around 100 B.C., another Greek made a similar rocket. Rockets were used by the Chinese during the Mongol empire. These were not rockets used for space exploration, but rockets don’t have to do that. Rockets can be simple; in fact you can build a model rocket yourself. They can also be as complicated as taking
 Figure 1 The first rocket to land on the moon, carrying Neil Armstrong

people into space and keeping them safe. In 1806, an Italian named Claude Ruggieri shot small animals into space. People started to get extremely enthusiastic about rockets which eventually lead to the rocket carrying people into space shot towards the sky.

How a Rocket Works

Newton’s third law states that every action has an equal and opposite reaction. On a rocket, the action is the rocket shooting high-powered gas out of the bottom and the reaction is the rocket shooting upwards. Newton’s second law states acceleration equals mass times force. The rocket has a colossal fuel tank that holds the fuel required to supply the force of the rocket to get into space. The mass of the rocket comes from the weight of the fuel. The acceleration of the rocket is needed to create thrust, which is required to get something off of the ground. The acceleration is first required to have force and mass. The rocket’s fuel tank takes up two-thirds of the rocket, so it has a lot of potential energy. When that potential energy becomes kinetic energy, the rocket is going to have a lot of force to get off the ground, which it needs because most rockets made for space exploration weigh about 4.4 million pounds. As the fuel tank burns more and more fuel, the rocket is reaching space. In an almost weightless environment, it takes less force to keep a rocket at a constant speed. That is when Newton’s first law comes into play. Newton’s first law states that any object in motion will stay in uniform motion until acted on by an outside force. The rocket will continue gliding forwards at the same speed with little help until it reaches its destination.

 Figure 2 A diagram of a rocket using inertia to continue moving in space

Examples of Newton’s Laws and How Work

If you were to throw a baseball on the moon, you would float a few feet backwards. If you wanted to move backwards at a faster speed, in other words accelerate more, then you would either need to put force on the baseball or more mass. To put more force on the ball, you would have to throw it with more velocity. To increase the mass of the ball, you would have to throw a bigger ball. Another example is how a twelve gauge shotgun kicks back at your shoulder when you fire it. This is because of the action of the bullet being fired and the reaction of the gun kicking backwards. Another example is balloon and how once you blow it up and let it go, it flies crazily around the room. This is because the action of the air being let out propels the balloon forwards.
 Figure 3 A rocket being shot into space using Newton's Three Laws

Glossary:
Acceleration: a change of speed in an object can be speeding up or slowing down. A rocket is required to have enough positive acceleration to reach space.
Kinetic Energy: the energy of an object in motion. A rock

et builds up potential energy and eventually releases it so it becomes kinetic energy during flight.
Mass: the amount of matter in an object, the density of an object. In a rocket, most of the mass comes from the fuel.
Uniform Motion: an object moving at a constant speed in a constant direction. A rocket is in uniform motion once it reaches space.
Citations:
Brain, Marshall. "How Rocket Engines Work" 01 April 2000. HowStuffWorks.com. 23 September 2012.
Brain, Marshall, and Inc HowStuffWorks. Marshall Brain's more how stuff works. New York: Wiley Pub., 2003. Print.
Kerrod, Robin, and Sharon A. Holgate. The way science works : discover the secrets of science with exciting, accessible experiments. New York, NY: DK Publishing, 2002. Print.
"Newton, Isaac." Compton's by Britannica. Encyclopedia Britannica Online School Edition.
Encyclopedia Britannica, Inc., 2012. Web. 13 Sept. 2012.