價格：免費
檔案大小：14.4 MB
版本需求：需要 iOS 8.0 或以上版本。與 iPhone、iPad 及 iPod touch 相容。
支援語言：英語
About
an open source physics at Singapore simulation based on codes written by Todd Timberlake, Fu-Kwun Hwang, Francisco Esquembre and Loo Kang WEE.
more resources can be found on support URL
Introduction
An object projected horizontally near the Earth’s surface follows parabolic trajectories as shown ( v = 0 red, v = 2000 green, v = 4000 blue, v = 6000 yellow and v = 8000 teal) .
As the speed of projection v increases, the object will reach a speed approximately v = 7888 m/s where the trajectory follows the curvature of the Earth’s surface
If air resistance is negligible, the object will orbit round the Earth continuously and will never meet the Earth’s surface such as speed v 8000 red m/s and v = 10000 m/s green.
Many man-made satellites move in circular orbits around the Earth. The first man-made satellite, the “Sputnik 1”, was launched by Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth. The only force acting on a satellite in a circular orbit (achieved by launching horizontally at vx =7276.69 m/s at height above Earth surface H = 0.185 RE where RE = 6370 000 m is the radius of Earth, is the Earth’s gravitational force. The gravitational force (red arrow is directed towards the centre of Earth) is also the the centre of the circular orbit.
This is a Lab that allows the exploration of this in a two dimensional space.
Interesting Fact
This app produce real numbers to coincident with the real world data.
Acknowledgement
My sincere gratitude for the tireless contributions of Francisco Esquembre, Fu-Kwun Hwang, Wolfgang Christian, Félix Jesús Garcia Clemente, Anne Cox, Andrew Duffy, Todd Timberlake and many more in the Open Source Physics community. I have designed much of the above based on their ideas and insights.
This research is supported by the eduLab project NRF2015-EDU001-EL021 , awarded by the Prime Minister Office, National Research Foundation (NRF), Singapore in collaboration with National Institute of Education (NIE), Singapore and the Ministry of Education (MOE), Singapore.
支援平台：iPhone, iPad