7.5. Key Concepts http://www.ck12.org
7.5 Key Concepts
- For something in orbit, an orbital period,T, is the time it takes to make one complete rotation.
- If a particle travels a full circle or orbit — a distance of 2πr— in an amount of timeT, then its speed is
distance over time or^2 Tπr. - An object moving in a circle has an instantaneous velocity vectortangentialto the circle of its path. The force
and acceleration vectors point to the center of the circle. - Net force and accelerationalwayshave the same direction.
- Centripetal acceleration is just the acceleration provided by centripetal forces.
- Ageosynchronousorbit occurs when a satellite completes one orbit of the Earth every 24 hours. Since it
revolves at the same rate as the earth, it will stay above the same location.