Background ➟ History of Rocket

Wooden bird  ➟ 

• principle of action-reaction
• Chinese Fire Arrows, the real rocket was born

Hero of Alexandria, invented a similar rocket-like device called aeolipile. It used steam as a propulsive gas.

In the first century A.D., the Chinese created explosions during religious festivals, they filled bamboo tubes with a mixture and tossed them into fires.

The Chinese began experimenting with the gunpowder-filled tubes. At some point, they attached bamboo tubes to arrows and launched them with bows. Soon they discovered that these gunpowder tubes could launch themselves just by the power produced from the escaping gas. The true rocket was born.

The first use of true rockets was in 1232. At this time, the Chinese and the Mongols were at war with each other. During the battle of Kai-Keng, the Chinese repelled the Mongol invaders by a barrage of "arrows of flying fire."

After the battle, the Mongols produced rockets of their own and may have been responsible for the spread of rockets to Europe.

Modern Rocketry Begins

Russian schoolteacher, Konstantin Tsiolkovsky

proposed the idea of space exploration by rocket. In a report he published in 1903, Tsiolkovsky suggested the use of liquid propellants for rockets in order to achieve greater range.

Early in the 20th century, an American, Robert H. Goddard, conducted practical experiments in rocketry. He published a pamphlet in 1919 entitled A Method of Reaching Extreme Altitudes. It was a mathematical analysis of what is today called the meteorological sounding rocket.

Goddard's earliest experiments were with solid-propellant rockets. In 1915, he began to try various types of solid fuels and to measure the exhaust velocities of the burning gases.

1.    Conservation of momentum ➟ 

Thrust push the rocket forward 

Sample Calculation

0 =Mr •  V​r↾+Mf  • Vf⇂

3.    Acceleration ➟ 

When the fuel thrust out of the rocket, it has a huge force that pushes down, and so the acceleration occurs.

Sample Calculation

4. Escape speed ➟ 

    a critical starting speed that permits a projectile to outrun gravity and to escape Earth.

How does it solve the real-life problem?

Rocket had been used in military, but now it is a tool for human to understand outer space and the universe. By launching rockets to the outer space, human gets to know things that we cannot see from the earth.

References

"Force and Momentum." Rocket Principles. Web. 1 Jan. 2015.

Web. 3 Jan. 2015<http://www.philsrockets.org.uk/physics.pdf>.

"Brief History of Rockets." Brief History of Rockets. Web. 3 Jan. 2015<http://www.grc.nasa.gov/WWW/k12/TRC/Rockets/history_of_rockets.html>.

NASA. NASA. Web. 3 Jan. 2015. <http://www.nasa.gov>.

"Presenting the Wonders of the Universe." Presenting the Wonders of the Universe. Web. 3 Jan. 2015. <http://www.guidetothecosmos.com>.

Web. 3 Jan. 2015. <http://www.real-world-physics-problems.com/rocket-physics.html >.