Light and Sound Flashcards
define a luminous and non-luminous object and give an example
a luminous object is an object that releases light and a non-luminous object doesn’t release light
e.g. the sun
e.g. a shoe
how does light travel
in straight lines
describe an experiment to prove that light travels in straight lines
Take several cards of paper and cut a small hole in each. Line up the holes in a straight line and shine a torch through. the light will reach the other side. However, if you move one of the cards so it is not a straight line, the light cannot pass through
describe how to draw a light diagram with arrows
*light starts at what the luminous object is shining on
*a line leads from it to another object (can happen more than once)
*the line reaches our eye
*there are arrows in the middle of the lines
describe an experiment to show reflection (and be able to label it)
- Put a light box facing a mirror
- Draw a straight line from where the light touches the mirror
- Both angles will be equal
first angle = angle of reflection
second angle = angle of incidence
what colours are in the rainbow
Red
Orange
Yellow
Green
Blue
Indigo
Violet
how can colours be absorbed or reflected
*absorbed-absorbs all of the colours except the colour it is
*reflected-the colour from the spectrum which the objects is gets reflected into your eyes
how does sound travel using medium particle theory
they travel by causing vibrations in the particles
describe an experiment to show that sound needs a medium
Bell Jar Experiment (shows that sounds need a medium to travel in)
1. Put an electrical bell in the bell jar
2. Pump the air out of the jar (with a vacuum)
3. Turn on the electric bell
4. You can’t hear the sound (proves that sound needs something to travel through)
which medium does sound travel fastest through and why
solid as all the particles are close together
which is faster sound or light
light
know how to label a soundwave
Amplitude (height)-amp=louder
Wavelength (length)-length=long
Trough (lower) and crest (higher)-Letter position in alphabet (c is higher than t)
define amplitude, wavelength and pitch
amplitude = loudness of sound
wavelength = length of sound
pitch = how high/low a sound is (the more frequent a sound is, the higher its pitch)
how do humans hear sound
- A sound wave enters the ear and goes into the ear canal
- After it passes through the ear canal, it hits the eardrum
- The eardrum passes the vibrations through the middle ear to the cochlea
- The cochlea translates the vibrations into nerve signals and passes it on to the brain
- The brain interprets the nerve signals as sound
how can loud noises damage our hearing
- Overtime, it overworks the hair cells in your ear which leads to them dying
