By Alexis Lundy Savannah Sharp Donovan Miller Lukas Binau Satellite Motion By Alexis Lundy Savannah Sharp Donovan Miller Lukas Binau

Sate and Explain Major Concepts An earth satellite is a projectile that falls around the earth instead of into it. A satellite has to match the curvature of the earth perfectly, so that it continually falls around the earth instead of into it. The time it takes a satellite to orbit the earth depends on its distance away from the earth. A satellite must orbit about 150 km above the earth’s surface to keep from burning up like a “falling star” would. The time it takes for a satellite to orbit earth is called the “period”. For a satellite close to the earth, the period is about 90 minutes. A satellite with a higher altitude has a lower orbital speed and a longer period. Communication satellites, located 5.5 earth radii above the earth’s surface have a period of 24 hours.

Historical Perspective Satellite Motion was understood by Sir Isaac Newton, stating that at a certain speed a cannonball would circle the earth and coast forever, if there was no air resistance. He calculated the required speed to be equivalent to 8 kilometers per second. At that time it was impossible for something to travel at that speed, and satellite launching wasn’t even imaginable.

Application of Concepts There are approximately 1,110 active satellites orbiting the earth, however there are approximately 2,000 more that are no longer working. Russia was the first to master the concept of satellites- launching the very satellite, Sputnik 1, in 1957. It had a orbital period of 98 minutes, an orbital height of about 577 kilometers, and was approximately the size of a beach ball. Technology has advanced in the last 60 years- the International Space Station is the size of an American football field and has an orbital period of 1.5 hours and an orbital height of 408 kilometers

Think and Explain Answers 1. Because the gravitational force of the Earth is greater than the moons 2. the speed of the sattelite depends on the height and mass of the earth, not the mass of the sattelite. 3. If the cannonball reaches a certain amount of speed so it goes into orbit, the gravity wont change the speed. 4. Because they are actually moving, but they are moving with the earth. 5. Less more because the gravitational field near the moon's surface is. weaker than the gravitational field near the earth's surface.

Think and Explain Answers 6. Because the rocket wouldn’t have to fight the earths gravitational pull longer. 7. Drop it a while before. 8. 11.2km/sec 9. Yes it is. 10. Yes.

Review Answers 1. If you drop a stone, it will fall 4.9 m in the first second. The same is true for anyting that begins to fall as it moves. If you could throw the stone 8000 m in a second, then it would begin to follow the curvature of the Earth. 2. For ever 8000m traveled, the surface of the Earth's curves down 4.9m away from the tangent line. 3. The satellite in ordbit above the Earth is moving forward at 8000 meters per second, and dropping towards Earth at a rate of 4.9 meters per second. 4. Gravitational force does not change the speed of the satellite because there is no component of gravitational force horizontally. The force of gravity is at a right angle to the direction of motion. 5. A) The period of a satellite orbiting the Earth is 90 minutes. B) If the satellite were farther from the Earth, the period would be longer

Review Answers 6. An ellipse is a specific curve: the closed path taken by point that moves in such a way that the sum of its distances from two fixed points (called foci) is constant. 7. Gravitational force changes the speed of a satellite in an elliptical orbit because it is not a perfect circle, and the satellite varies in difference in distance from the Earth. 8. A) The maximum speed of the satellite in the elliptical orbit is when the satellite's kinetic energy is at its greatest (the perigee). B) It is minimum when the potential energy is at its greatest, and the satellite is at its apogee. 9. Yes, it is also constant in both circular and elliptical orbit.

Review Answers 10. The force of gravity does no work on a satellite in circular orbit because the distance from the satellite to the Earth is constant, this is not true for a satellite in elliptical orbit which moves away from the Earth as it orbits. 11. A) It will crash back down to Earth at a speed of 8 km/s. B) The projectile will be slowed by Earth's gravity, but it will eventually escape and not be stopped. 12. The Earth's gravity is only strong close to the Earth. The farther away you are from Earth, the less gravity there is.

Review Answers 13. A) A particle would have to have an escape speed of 620 km/s to leave the Sun's gravitational pull. 14. The escape speed for the mood is 2.4km/s. 15. Yes, as long as the rocket's speed remains greater than 0 km/s and it has a long enough time.

Background Information "Newton's cannonball", by Isaac Newton was the first published mathematical study of the possibility of an artificial satellite. The first fictional depiction of a satellite being launched into orbit was a short story by Edward Everett Hale, The Brick Moon. The idea surfaced again in Jules Verne's The Begum's Fortune

Question and Hypothesis How can we demonstrate a Satellite orbiting a Mass? I believe that we can demonstrate a satellite orbiting a mass by swinging a can around a person

General Statement We will tie a rope to a can and then have person swing it around there body to demonstrate what satellite motion looks like

Apparatus 1. Soda can 2. Rope 3. Penny

Step-by-Step 1.We will tie a rope around the lid of the can 2. Put a penny inside of the can to also demonstrate the centripetal force satellites can produce 3. Have a person swing a can around them

Safety Precautions Be sure to have ample space so nothing gets hit with the can

Collecting Data So the amount of speed it takes for an object to orbit the earth takes is 8000 meters per second (28800 km/hour) and at that the friction from air resistance would burn a rock to a crisp. This is needed to achieve orbit due to the fact that for every 8000m traveled the earth drops 4.9m. Because we can't physically send anything into orbit in the classroom, we have to just demonstrate what orbit looks like.

Analysis In conclusion, this is an effective way to demonstrate what satellite motion looks like, but if you are looking for measurements this is not the experiment for that.

Conclusions The things that were being demonstrated where how a satellite orbits a mass and how centripetal force can also come into play.

Evaluation of Hypothesis and Question Our question was answered because we were able to demonstrate satellite motion. The hypothesis can be accepted because this demonstration proved that it can demonstrate satellite motion.