P5 Revision Notes

These are revision notes that cover all of P5, I hope you find them useful!

HideShow resource information
  • Created by: Clairee
  • Created on: 20-06-11 14:47
Preview of P5 Revision Notes

First 136 words of the document:

P5a ­ Satellites, Gravity and Circular Motion
A satellite is an object that orbits another object in space because of the force of
gravity
Uses of Artificial Satellites
Monitoring weather or climate.
Communications e.g. Phone and TV.
Space Research, Hubble Telescope.
Spying.
Navigation e.g. GPS.
Geostationary Orbit Satellites
1) In a high orbit over the equator ­ 35800km.
2) Takes 24hrs to complete orbit (period).
3) Ideal for communications and weather because they're above a fixed position on the
Earth.
LowPolar Orbit Satellites
1) In a much lower orbit, it passes over the Earths poles.
2) Takes a couple of hours to complete orbit (period).
3) Ideal for spying and weather because they have low orbits so can take good photos

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Gravitational Force
A universal force between masses and varies with distance
The bigger the mass the bigger the gravity (force)
The further apart the objects the smaller the force
Orbital Period varies with height
The higher the satellite is above Earth the slower the orbital period is because there is less
attraction between the object and the Earth
The closer the orbit the faster it goes because there is more attraction
It is an inverse square relationship
Motion of a Comet
Comets have elliptical orbits…read more

Page 3

Preview of page 3

Page 4

Preview of page 4

Here's a taster:

P5b ­ Vectors and Equations of Motion
Speed is a measure of how fast an object is moving. Velocity is speed in a given
direction.
Scalar Quantities
Scalar Quantities only have magnitude (size).
Examples: distance, speed, energy, mass and time.…read more

Page 5

Preview of page 5

Here's a taster:

P5c ­ Projectile Motion
A projectile is something that is thrown or fired the path it takes is the trajectory. On
Earth due to the gravitational field if the projectile is horizontal the object will always
follow a parabolic trajectory unless it has a jetpack!
Example: Calculating Projectile using the Equations of Motion
A ball is kicked horizontally from a 20m high wall. How long will is it before it will land?
It will land when it travels 20m vertically so...…read more

Page 6

Preview of page 6

Here's a taster:

U=0
V=
A= 10m/s
T= ?
If we ignore air resistance the projectile has...
Horizontally Vertically
No force Gravitational
No force downwards
acceleration Acceleration
Constant downwards
velocity Increasing
Velocity
downwards
Projectiles have a downward acceleration that only affects the vertical
velocity.
Projectiles have no acceleration in the horizontal direction.
The resultant velocity is the horizontal and vertical velocities added together.
Horizontal and Vertical Velocities are Vectors
You can use the equations of motion to work out horizontal and vertical
velocities.…read more

Page 7

Preview of page 7

Here's a taster:

On earth the acceleration is always 10m/s downwards. The initial velocity is
nearly always 0.…read more

Page 8

Preview of page 8

Here's a taster:

P5d ­ Momentum
Every action has a equal and opposite reaction. The formula for momentum is:
Momentum = Mass x Velocity
Conservation of Momentum
The momentum before a collision is always equal to the momentum afterwards. It relies on
the fact that momentum is a vector and has direction as well a size.
Explosions
The total momentum before is 0
After the explosion the pieces go in all directions, but the total momentum of all the pieces
added together will still be 0.…read more

Page 9

Preview of page 9

Here's a taster:

Crumple Zones are designed to fold in a collision increasing the time taken to stop so
therefore reducing the force on the passenger.
Injuries in a sports accident and those caused by car accidents are caused by a
very rapid acceleration of parts of the body.…read more

Page 10

Preview of page 10

Here's a taster:

P5e ­ Satellite Communication
Radio waves are reflected off of the ionosphere and microwaves are be transmitted
to orbiting satellites.
Why are radio waves better for broadcasting
Radio waves have a large wavelength so they are diffracted around hills and over the horizon,
so they a spread out over a large range.
Microwave Information
Microwaves are transmitted to orbiting satellites because they have a very high frequency
(over 3GHz).…read more

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all resources »