U4: orbital motion

what is a geosynchronous satellite

satellite with an orbital period the same as earth’s rotation period (1 day)

• placed directly over the equator

• stays in a fixed position over the earth’s surface

why are geostationary satellites so useful

• a reciever can be aimed at the satellite at all times

• reciever can constantly recieve a signal from the satellite

• can construct a large, stationary satellite dish

• used in communication and navigation

what is the period of a geostationary satellite

1 day / 86400 s

a) How far away is a geostationary

satellite from the surface of the

earth (in m and km)?

b) What is its velocity in m/s and

km/h?

how do you calculate the height of a geostationary satellite above the surface of earth

radius of the satellite orbital radius - radius of earth

what are the 2 ways to find the velocity of a geostationary satellite

explain artificial gravity

Artificial gravity is a way of creating a gravity-like effect without using a massive planet, usually by rotation.

centripetal acceleration formulae

ac = v²/r → v = speed of the object, r = radius of its circular orbit

ac tells you the inward accerlation required to keep an object moving in a circle

how are the axes different for a ramp vs a banked curve?

how does this affect the FBD and Fnet?

for a ramp, the forces are acting along the ramp, so the axes are tilted so the x axis is parallel to the ramp

for a banked curve, the centripetal force (and acceleration) is acting directly towards the centre so the x axis is not tilted! the forces are not acting at a tilted angle!

Fnet acts along the axes, so make sure that when your writing Fnet equations, the forces ALONG the axes are being added up

draw the FBD for a banked curve

• which direction does friction act along

• positive directions? ac, ay?

notice that friction acts along the ramp because its the force between the object and the surface, gravity acts down ALWAYS, and Fn is perpendicular to the surface

show how the direction of centripetal acceleration is in the same direction as ∆v

what are the 3 formula for centripetal acceleration

what is centripetal force

centripetal force is a synonym for the net force towards the centre of a circle

B

what is apparent weight

this is the normal force

what you feel is the apparent weight. what are the 3 scenarios that you should feel?

what is g of force?

g = Fn/Fg

what features do you need in an explain question

-Definition (IF RELEVANT)

-Point form

-Diagram(s)

-Equations

-Summary/Conclusion