phys

Question 1

Uses of Low-Earth Orbit

Answer 1

Imaging
Easier to get into orbit

Question 2

Uses of geostationary orbit

Answer 2

Telecommunications
Weather
No moving dishes
Wider line of sight
Less drag

Question 3

AC Induction Motor

Answer 3

Three-phase electromagnets - out of phase
As the AC voltage is supplied, the superposition of the magnetic field forms a rotating magnetic field
Slip speed chased by the squirrel cage stator
Eddy currents

Question 4

Historical + Contemporay

Answer 4

Romer’s Measurement of Io
As observed from Earth, Io can be hidden behind Jupiter and the successive delays of the orbtial period is a consequence of light speed
Using the movement of Earth and light delays, Earth’s diameter as determined using Kepler
22

Fizeau’s Cogwheel
Adjusted rotational speed

Foucault
Rotating mirror onto a stationary mirror; constantly changing angle
Change in Angle + Angular speed + Time

Essen Cavity Resonator
Standing waves were formed in a cavity and resonated to determine the speed
Standing microwaves - AC frequency