Light + Sound Flashcards
Define a luminous and non-luminous object and give
examples of both. (4)
A luminous object gives out, or emits, its own light. (1)
Sun, Stars and Light Bulb… (1)
A non-luminous object does not give out its own light. (1)
Spoon, Table and Chair… (1)
True or False: Light travels in straight lines. (1)
True
Describe an experiment to prove light travels in straight
lines. (2)
Arrange three pieces of card, with holes in them, into an uneven line. Then position a luminous object so that they go through one of the cards. The light will eventually stop and cannot travel through all three cards. (1) When you arrange the holes in a straight line, the light can travel through. (1) This shows that light travels in a straight line.
Draw (Describe Here) a light diagram with arrows
PPT 6
Describe an experiment to show reflection, also be able
to label the diagram.
PPT 10 - 11
Draw and Label a Periscope
PPT 7
Describe an experiment to show refraction, also be able
to label the diagram.
PPT 17 - 18
Can white light be dispersed, name the
colours. (8)
Yes (1): red (1), orange (1), yellow (1), green (1), blue (1), indigo (1) and violet. (1)
Describe how we see colours, how colours can be
absorbed or reflected. (3)
When light hits a surface, some of it is absorbed and some of it is reflected. The light that is reflected is the colour of the object in that light. (1) For example, a blue object absorbs all the colours of the spectrum except blue: it reflects blue light, (1) which then reflects into our eyes, therefore we see light. (1)
Label a sound wave.
PPT 25
What is faster, sound or light? (1)
Light. (1)
Define amplitude, frequency and pitch and be able to
recognise their waves. (4)
Amplitude is the maximum height of the wave from its resting position. (1)
Frequency is the number of cycles of the waveform in one second. (1)
Pitch is how high or low the sound is. (1)
PPT 27 - 28 (1)
How we hear sounds and how loud noises can damage
hearing.
- A sound wave is funnelled into the ear canal by the pinna (1)
- The vibrations in the air make the eardrum vibrate (1)
- These vibrations are passed through the three small bones (the ossicles) to a spiral structure called the cochlea (1)
- Electrical nerve signals are passed from the cochlea to the brain through the auditory nerve (1)
- Our brain interprets these signals as sound (1)
Listening to loud noise for a long time can overwork hair cells in the ear, which can cause these cells to die. (1)
Which medium does sound travel fastest through and
why?
Solids. (1)
This is because the particles of gases are further apart than solids. Sound waves move more slowly when particles are further apart. (1)
Describe an experiment to show that sound needs a
medium. (1)
Bell Jar Experiment is used to demonstrate that sound needs a medium to travel. Place an electrical bell in the bell jar and pump out the air of the sealed bell jar. Turn on the electric bell. The sound produced by the bell is not audible to our ears. (1)
