Vectors And Scales Flashcards
RPA6- stretching a spring
- place heavy weight on clamp stand to stop it from falling over
- attach meter rule and spring
- top of string must be at 0 point on meter rule
- meter rule must be vertical or the readings will be inaccurate
- bottom of spring has wooden splint attached as pointer
- read position of pointer with meter rule
= is the un streched length of spring - hand 1N weight on spring
- read new position of pointer
- continue adding 1N weight
- subtract length of un stretched spring from each reading
Define moment
- turning effect of a force
How to accelerate without changing speed
Change direction and velocity
What’s the bottom of the wave
Trough
Describe time period
Time it takes for one complete oscillation
Wave speed equation
Wave speed = frequency X wavelength
Measurement for wavelength
Metres
Describe transverse wave
Oscillations are perpendicular to direction of energy transfer
Eg ripples, radio
Describe longitudinal
Oscillations are parallel to direction of energy transfer
Eg sound
What do wave movements depend on
Wavelength
Properties of the two materials
Describe diffuse reflection
Boundary is bumpy
= normals will all be different
= light will be reflected in different directions
Describe refraction of light waves
Waves change direction as they pass from 1 medium to another
What happens when light hits dense material at an angle
- light hits at an angle
= direction will change - light will bend towards the normal
Describe electromagnetic waves
Transverse
Travel at same speed in a vacuum
When I’m different mediums they travel at different speeds
= lead to refraction
Describe radio waves
Longest wavelength
Lowest frequency
Generate them using alternating electric current
Purpose of oscilloscope
See the frequency of the alternating current
= determines the frequency of wave produced
Describe a receiver
Absorbs energy
= generates alternating current displayed on another oscilloscope
= transfer information
Use of radio waves
Communication
Describe types of radio waves
Long waves
= transfer huge distances
= bend around curves surface of earth
Short waves
= travel long distances
= reflected on ionosphere
Short waves
= travel data short distances
Very short waves
= travel directly from transmitter to receiver
= on tv radio etc
Describe infrared radiation
Emitted from all objects that have thermal energy
See in dark
Spot living organisms
Describe electric heaters
Use retrieval energy to heat the metal
= emits infrared radiation to surroundings
Describe x rays and gamma rays
Shortest wavelength
Highest frequency
Use of x rays
View internal structure of objects
Quick and cheap test
Staff wear led aprons and leave room when rays fired
Use of gamma rays
Medical imaging
Kill cancer
Sterilise things
How do gamma rays sterilise things
Kill microorganisms without causing any other damage
Compare x rays and gamma in medicine
Both ionising
= can damage cells
= lead to cancer
Both diagnose and treat diseases
