Unit 3 Flashcards
Which way does light refract when passing from air to glass?
TOWARDS the normal (r<i)
Which way does light refract when passing from glass to air?
AWAY from the normal (r>i)
How does a LONGITUDINAL wave move?
In longitudinal waves, the particles vibrate in the same direction as the direction travel.
How does a TRANSVERSE wave move?
In transverse waves, the particles vibrate in right angles to the direction travel.
When will you see circular waves in diffraction?
When the gap that the waves pass through is smaller than the actual wavelength of the waves.
Name all waves in the Electromagnetic Spectrum.
Radio & TV
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma Rays
Give an example of an application for every wave type in the EM spectrum.
Radio & TV - Used for broadcasting
Microwaves - Radar technology
Infrared - Used for TV remotes
Visible Light - Makes things visible
UV - Suntan lamps
X-ray - Medical Imaging
Gamma Rays - To kill cancer cells
What is the law of reflection?
Angle of Incidence (i) = Angle of Reflection (r)
What is the principle of reversibility?
Light always travels in a straight line. If the direction of the ray of light is reversed, it will follow the same path, but in the opposite direction.
Give an example of a longitudinal wave.
Sound Waves
Give an example of a transverse wave.
Electromagnetic spectrum.
What is diffraction?
Diffraction is where a wave bends into the shadow region when passing an obstacle.
What is refraction?
Refraction is the change in speed of light when it passes from one medium to another. This results in a change in wavelength.
What do you call the part of a wave between the axis and crest/trough?
Amplitude
Define amplitude.
The distance between the trough/crest and the axis.
What is the crest?
The highest point of a wave.
What is the trough?
The lowest point of a wave.
What is the frequency of a wave?
How many times a wave passes a point within a second.
What is the wavelength of a wave?
The distance between 2 troughs/crests
What is the wave speed of a wave?
How far a wave travels in a second.
What is the period? (T)
The time taken for a wave to pass a point.
What is the formula for period?
Time taken / Number of events
Which wave in the EM spectrum has the largest wavelength?
Radio & TV waves
Which wave in the EM spectrum has the smallest wavelength?
Gamma rays
Which wave in the EM spectrum has the highest frequency?
Gamma rays
Which wave in the EM spectrum has the lowest frequency?
Radio & TV waves
What does MICRO mean?
10^-6
What does MILLI mean?
10^-3
What does KILO mean?
10^3
What does MEGA mean?
10^6
What does GIGA mean?
10^9
What quantity is speed?
Scalar — Direction is not important
What quantity is velocity?
Vector — Direction is important
What quantity is weight?
Vector — It has a magnitude and direction
What is a magnitude?
Magnitude is how much there is of something, or how large something is, but not which direction it moves in.
What is a vector quantity?
A quantity which has both a magnitude and direction.
What is a scalar quantity?
A quantity which has a magnitude, but no direction
What is the formula for calculating average speed?
Average Speed = total Distance/total Time
What is the formula for calculating instantaneous speed?
Instantaneous Speed = Very small Distance / Very short Time
What is the formula to calculate power rating?
P = IV
P = E/t
When would the formula for gravitational potential energy be used?
When something is subjected to gravity (ie. when a mass is being lifted)
What is the formula for gravitational potential energy?
E = mgh
———
E = Gravitational Potential Energy (J)
g = Gravitational Field Strength (Nkg-1)
h = Height (m)
When a satellite orbits a planet, what stays constant?
The horizontal speed of the satellite
Does a satellite move when orbiting a planet?
No (don’t ask why)
Is a satellite weightless when orbiting a planet?
No.
What is the speed of light?
3x10^8
What is distance?
Distance (d) is the total length of the path traveled by an object, regardless of direction.
- It is a scalar quantity (has only magnitude)
- Unit: Meters (m).
- Always positive and never decreases.
What is displacement?
Displacement (S) is the shortest straight-line distance from the starting position to the final position, with a specific direction.
- It is a vector quantity (has both magnitude and direction).
- Unit: Meters (m).
- Can be positive, negative, or zero depending on direction.
