Space for reflection

Space for reflection

1. Satellites and gravity

   • Geostationary satellites takes 24 hrs to orbit Earth above the equator, meaning they stay in a fixed position.
   • Low Polar satellietes orbits the poles (N & S). The Earth spins as the satellite move so it can sacn the whole surface of Earth
   • Gravitational force keeps satellites in orbit
   • Centripetal force is the force on any object moving in a circle that is towards the center of the circle to maintain its circular path.

2. Satellite Communication

   • Some radio waves are refelected by the ionosphere
   • Microwaves pass through ionsopshere to reach an orbiting satellite
   • Long wavelength radio waves are eaisly diffracted around hills; short wavelength radio waves only diffract a small amount

3. Scalars and vectors

   • Scalar = size
   • Vector = size and direction
   • Momentum is a vector and is always conserved
   • Changes in temp and volume can cause changes in pressure. Rate of change of momentum creates a force on the walls of the container
   • Projectiles have a constant horizontal velocity, have a parabolic trajectory and accelerate towards the ground at 10m/s2

4. Waves

   • Polarised light oscillations in one direction only
   • Interference occur when two waves overlap. They can reinforce or cancel. The type of interference is dependant on the oath difference between two waves.
   • TIR can occur when light goes from a dense to a less dense medium. TIR happens in an optical fibre.