Out into Space- Physics B G494

• Kepler's Laws: 1. The sun is situated at one of the foci of the ellipse.

2. The area swept by the path of a planet in orbit is constant.

3. The orbital period if a planet was related to its mean radius (Period²∝Radius³)

• Retrograde motion: when it looks like planets went back on themselves and looped.
• Centripetal Force- Planets in orbit accelerate as their direction changes, therefore there must be a force. This force acts towards the centre.

Equations for Centripetal forces: 

Angular velocity (ω) = angle / time (rads^-1) For one complete revolution, ω= 2π/T

a=rω²=v²/r                                                         F=mrω² = mv²/r

• All particles…