5-7 Flashcards
What is a scalar?
Just a number ( E.g distance, mass, speed)
What is a vector?
A number and direction (E.g displacement, weight, acceleration, force and momentum)
What does the resultant force equal?
Resultant force = difference between forces.
Equation for weight?
w = m x g
weight - (n)
mass - (kg)
gravity - (n/kg)
What is the equation for work?
w = f x s
work - (j)
force - (n)
distance - (m)
What is 1 Joule equal to?
1 Joule is equal to 1 N/m
What is Hooke’s law?
When you exert a force on an object it is going to be squashed, stretched or deformed.
What happens to a spring if you attach more weight?
More weights added = longer spring.
What is the limit of proportionality?
Where no matter how much more weight is added the spring will not stretch any further.
What is the equation for acceleration?
a = (change in) velocity/time
acceleration - (m/s^2)
velocity - (m/s)
time - (s)
Change in velocity equation?
v^2-u^2 = 2 x a x s v(final velocity) - (m/s) u(initial velocity) - (m/s) a(acceleration) - (m/s^2) s(distance) - (m)
Speed of free fall and also gravity?
s= 9.8m/s g= 9.8n/kg)
When is terminal velocity reached?
When all forces are balanced.
Equation for Force?
f = k x e
Force - (n)
Spring constant (k) - (n/m)
extension (e) - (m)
Kinetic Energy equation?
Ek = 1/2 x m x v^2
Kinetic energy (Ek) - (J)
Mass (m) - (kg)
Velocity (v^2) - (m/s)
Equation for pressure?
-Involving force and area
P = F/A
Pressure (P) - (Pa_Paschal)
Force (F) - (N)
Area (A) - (m^2)
Equation for distance?
s = v x t
Distance (s) - (m)
Velocity (v) - (m/s)
Time (t) - (s)
Pressure equation?
-Involving height, density and gravitation field strength
P = h x p x g
Pressure (P) - (Pa_ paschal)
Height (h)- (m)
Gravitational Field Strength (g) - (9.8n/kg)
Liquids are…
Incompressible
Gases are…
Compressible
Equation for Force?
-Involving mass and acceleration
F = m x a
Stopping Distance =
Thinking Distance + Braking Distance
Things that effect thinking distance?
Alcohol, drugs, Tiredness (Positive is Caffeine)
Things that Effect Braking Distance?
Conditions of tyres
Condition of road
Weight of car
Car Safety?
Seat belts
Baby seat
Crumple Zones
Airbag
Momentum equation?
-Involves mass and velovity
P = m x v
What is the law of conservation of momentum?
Momentum is always conserved so the moment before = moment afterwards
What is inertia?
An object that is in motion will remain in motion, unless acted on by and outside force.
An object in rest will remain in rest unless acted by an outside force.
What is Newton’s third law?
Where for every action there is an equal and opposite reaction.
The law of conservation of energy?
Energy is never created or destroyed, only transformed into something else. (Usually Heat)
What do we use to measure the speed of a wave?
Ripple Tank
Equation for wave speed?
Wave speed = f x wavelength (lamba)
Radio waves have what sort of energy? frequency? and wavelength?
Low energy
Low frequency
Long wavelengths
Gamma rays have what sort of energy? frequency? and wavelength?
High energy
High frequency
Short wavelength
Transverse waves movement?
Up and down
Longitudinal wave movement?
Sideways (to the right)
Low frequency means..
Not many peaks but a high wavelength.
High frequency means..
Lots of peaks but a low wavelength.
Frequency is..
Number of waves per second.
To calculate frequency?
T = 1/f
f- frequency
Rare fraction and compression on a longitudinal wave?
Rare fraction = not many dots
Compression = lots of dots together
Good absorbers:
Good emitters:
Good reflectors:
Good absorbers: dark and matt
Good emitters: dark and matt
Good reflectors: shiny
How can you induce a magnet?
You can induce a magnet by putting something in the magnetic field.
Magnetic materials?
Iron Nickel Cobalt
What is diffraction?
Diffraction happens when a wave passes through a gap, the wave will curve around as it comes out that gap. The amount of curviture (diffraction) depends on the size of the gap.
What is refraction?
Refraction is when a wave passes from one medium to another medium. It will change direction because the wave changes speed but different part of the wave changes speed at different points.
How can you change the strength of an electromagnet?
Change current
Change amount of coils
Left hand rule- fingers
Thumb is Movement
Index finger is field
Current is middle finger
How can you make an electro magnet?
Battery Wire Iron Nail
How does electromagnetism work?
- When a current is passed through a wire it creates a magnetic field around the wire.
- This in turn strongly magnetises the iron bar.
- Thus creating the electromagnet.
How does a Moving coil loudspeaker work?
Works by making a diaphragm attached to a coil vibrate.
- Current is passed through coil, this generates a force.
- Each change in direction causes a change in vibration in the diaphragm.
How does a Moving coil microphone work?
Vibration causes the coil to move past a magnet, generating current.
- Vibration causes coil to move past a magnet, generating current.
Force is greatest when the wire is _______ with the magnetic field lines.
Perpendicular.
The force is 0 when the magnetic field lines are _______.
Parallel.
What is magnetic flux density?
Amount of magnetic flux in a certain area.
Force equation?
- Involves magnetic flux density, current and length
F = B x I x L
Sound waves are what waves?
Longitudinal.
Range of human hearing?
20Hz to 20KHz
What can ultra sound be used for?
Determining distance + pregnancy.
Speed equation?
-Involving distance and time
S = D/T
Unbalanced forces have what forces?
Unequal.
Balanced force have what forces?
Equal.
Moment equation?
- Involving force and distance
M = f x d
Force equation?
- Involving mass and velocity and time
f = (mx change in velocity)/change in time
Angle of incidence =
Angle of reflection
When sound waves are reflected they..
Echo
What are p waves + properties?
Primary waves
- longitudinal
- solids and liquids
What are s waves + properties?
Secondary waves
- transverse
- solids
What do converging lenses do?
Correct long sightedness
- real image
- magnified
What do diverging lenses do?
Correct short sightedness
- virtual image
- upright
- small
Magnification equation?
Magnification = Image height/ object height (MIA)
Red colour properties:
Freq = 4 x 10^14 Hz Wavelength: 7 x 10^-7m
Violet colour properties:
Freq = 7 x 10^14 Hz Wavelength: 4 x 10^-7m
Tranformer Calculations:
Vp/Vs= Np/Ns . Vs x Is = Vp x Ip
Step up transformer voltage?
Secondary voltage Vs > Primary voltage
Step down transformer?
Secondary Voltage Vs < Primary voltage
What is a black body?
Black body is an object in space which absorbs radiation.
What emits infrared radiation?
Everything
The Generator Effect?
Movement of wire through a magnetic field produces a current.
Plants in order
My Very Easy Method, Just Speeds up Naming,
What galaxy do we live in?
Milky Way
If a galaxy is coming towards us what type of light?
Blue shifted
If a galaxy is moving away from us what type of light?
Red shifted
What is speed?
How fast you are going. Scalar
What is velocity?
How fast you are going in a certain direction. Vector.
Red shifted properties?
Increased wavelength
Decreased frequency
Blue shifted properties?
Decreased wavelength
Increased Frequency
