Physics Test S2 Flashcards
Why couldn’t we see the tuning fork clearly
Because it was vibrating so fast
What happened to the ball after it hit the tuning fork
The ball jumped away suddenly due to the vibration
How did the tuning fork make noise
Through vibrations
What are all sounds made by
Vibrations
What is frequency?
The frequency of a sound is its pitch
What is amplitude?
How loud a sound is
What does a wave with high amplitude and high frequency look like?
Tall waves and lots of them close together
What does a wave with low amplitude and low frequency look like
Short waves with only a few waves far apart
What is a wavelength
The distance between any two adjacent crests
What is the line of zero disturbance
Represents a zero amplitude wave (no wave present)
What is the formulae for finding frequency
f=N/t
What is frequency
Number of whole waves produced each second
What can the human ear do?
It can detect sounds within a certain range of frequencies
What 3 animals can hear ultrasound
Bat
Dolphins
Moths
What 3 animals can hear infrasound
Elephant
Whales
Peacocks
Briefly describe the path of light as it passes through the ray box?
When the incidence ray passes into the Perspex into the perpexs at 90 degrees to the normal it does not change paths.
In optics the angles are always measured the?
Ray and the normal
What is refraction?
The change in speed which occurs when light passes through one optical medium to another
What happens when the incident ray goes from air to glass:
The ray bends towards the normal
What happens when the emergent ray goes from glass to air?
The ray bends away from the normal
What do you notice about the directions of the incidents ray and the emergent ray?
Emergent ray is parallel to the incidence ray
Describe what happens to light rays after they enter the Perspex {converging lens}
The light rays start off parallel but go through the converging lens and then are refracted and converge on a focal point
Describe what happens to light rays after hitting the perspective {diverging lens}
The parallel light rays come from the ray box and hit the diverging lens and become refracted light rays that have diverged from the diverging lens
What happens to the image after using the converging lens
It flips upside down and horizontal
It is also smaller than the actual thing
Are thicker or thin lenses more powerful?
Thicker lenses
What is the formula for optical power?
P=1/f
Are convex lenses positive or negative for focal lengths and optical powers
Positive
Are diverging lenses positive or negative in optical power or focal Lents
Negative
What does the cornea do?
The transparent outer lens which does most of the eyes refraction
What does the pupil do?
A hole that allows the light in , it changes size according to how bright it is
What does the lens on an eye do?
Focus’s the light onto the retina , changes thickness to vary the amount of refraction
What does the retina do
The light sensitive coating at the back of the eye retina cells changes light energy into the retina to the brain
Why do u think the brain causes the pupil changes in size when the light level changes?
It changes to limit light in and changes to take in as much light as it can find
What is the blind spot
The point in the retina at which the optic nerve is connected cannot detect light because here are no light sensitive cells light from an object landing on the blind spot cannot be seen
What is the human hearing range
20hz to 20,000
