how do scientists work Flashcards
(22 cards)
Two types of questions could be:
Are these the same or are they different?
E.g. Are the trees in this field taller than the ones in that field?Is this thing related to that thing?
People with bigger feet normally have bigger hands. Is foot and hand size related?
Is this thing related to that thing?
If I change this thing, does the other thing change too?
What types of wave are there?
light,
sound,
ocean waves,
radio waves,
ultraviolet radiation
What do waves do?
Waves transfer energy from one place to another.
Light waves
from the Sun travel through space and through the atmosphere, transferring energy to the Earth and other planets.
Sound waves
travel from a loudspeaker and transfers energy to the objects which absorb it for example, your ears.
transverse waves.
Some waves move through a substance because the particles vibrate at right angles to the direction that the wave is moving in, these types of waves are called
longitudinal waves.
Other waves travel because the particles move backwards and forwards a short distance in the same direction as the wave is moving in. These types of waves are calle
Describing transverse waves
Peak – the highest point of a transverse wave is called a peak, like the highest point of a mountain
Wavelength – The distance from one peak to the next peak or one trough too the next rough is called the wavelength.
Amplitude – the distance from a peak or a trough to the rest position
Trough – the lowest point of a transverse wave is called a trough because it looks like a trough that an animal might eat from.
Frequency
Frequency – the number of complete vibrations in one second. This is the same as the number of complete waves passing a point each second. Frequency is measured in hertz (Hz). A frequency of 50 Hz means there are 50 vibrations every second, or that 50 waves pass by every second.
Investigating longitudinal waves
Sound waves, pressure waves and primary waves ( a type of seismic wave produced by earthquakes), are longitudinal waves. Longitudinal waves can also be made by pushing a slinky forwards and backwards,
Describing longitudinal waves waves
The distance from the centre of one compression to the centre of the next compression is called the wavelength. The wavelength of a longitudinal wave could also be measured from the centre of a rarefaction to the centre of the next rarefaction.
How is sound produced?
Sound is produced when an object vibrates. When something vibrates, it moves back and forth very quickly. These vibrations create waves of energy that travel through the air or other materials.
When sound waves reach our ears, they cause our eardrums to vibrate. These vibrations are then transmitted to tiny bones in our ears, which send signals to our brain. Our brain interprets these signals as sound, allowing us to hear.
A louder sound has a higher
AMPLITUDE.
This means that a louder sound must have a larger
VIBRATION
Frequency of a sound wave
The frequency of a sound is how many waves there are in a second, and it is measured in Hertz (Hz).
How does the ear hear?
1.Sound waves are collected by the ear lobe or pinna.
2.The waves travel along the ear canal.
3.The waves make the ear drum vibrate.
4.The small bones (ossicles) amplify the vibrations.
5.The cochlea turns these into electrical signals.
6.The auditory nerve takes the signals to the brain.
REFLECTION OF SOUND
Hard, flat surface: strong echo
The sound waves REFLECT off of the surface
Soft, absorbing surface
weaker echo
Some of the sound waves REFLECT off of the surface, some is ABSORBED by the surface
What comes first?
Light travels faster than sound – more of that later
Speed of Sound Practical equation
Speed (m/s) = distance (m)➗ time (s)
Which state does sound travel fastest through? Why?
Sound travels fastest through solids because the particles are closer together than in a liquid and a gas, so the vibrations are more easily passed from particle to particle.
