Physics Paper 2 Flashcards
(29 cards)
Contact force
When objects physically touch e.g. normal reaction force. friction, air resistance and tension
Non-contact force
When objects do not touch e.g. magnetism, electrostatic force and gravity
Scalar
Only has magnitude
Vector
Has Magnitude and direction
Gravitational field strength
Here on Earth is is 9.8N/kg
Springs
Any object that defors elastially will return to its original shape and must obe Hookes Law.
Springs RP
Add masses onto spring to change force (e.g. 100g=1N)
Measure extention with ruler at each weight, plot F against E
Gradient of graph= Spring constant
Avoid systematic error by lining up 0cm with bottom of spring
Avoid parallax error by getting on eye level when measuring
Distance time graph
gives you speed/velocity
Velocity time graph
gives you acceleration
Area under graph gives you distance/displacement
Newtons 1st Law
If the forces are balenced then the object will remain at constant velocity or stay stationary
Newtons 2nd Law
Force = mass x acceleration
Newtons 3rd Law
For every force there is an equal and opposite reaction
Force = mass x acceleration RP
Accelerate trolly on track with slotted mass on string over pully
Use light/photogated to measure acceleration
Change force by removing masses and placing on trolley (to keep total mass the same)
Plot F against a, gradient= total mass
Stopping distance
=Thinking distance + braking distance
Thinking distance is affected by:
-speed
-distractions
-alcohol
-drugs
-tiredness
Braking distance is affected by:
Weather conditions
condidtion of brakes,tyres and road
Momentum
=M x V
In any collision, Total momentum is always conserved
Longitudinal waves
The direction of oscillation is parralel to the direction of energy transfer e.g. sound
Consists of COMPRESSIONS and RAREFRACTIONS.
Transverse waves
The direction of oscillation is perpendicular to the direction of energy transfer e.g. water waves or light
Wavelength
Length of one complete wave
Time period
The time taken for one wave to pass by a specififc point
Frequency
The number of waves that pass every second
Electromagnetic spectrum
Long to short Wavlength
Radio waves-Phones,tv,wifi
Microwaves-cooking
Infared- cooking
Visisble light-vision
Ultra violet-Tanning,cause cancer
X-rays-medical scans,also dangerous
Gamma rays-sterilising medical treatment also dangerous
Infared RP
Use leslie cube with infared thermometer or tubes wrapped in different materials under source e.g. IR lamp , shiny materials are the worse, anything black works best
Refraction
When waves enter a new medium (material) their speed changes, so does their angle
only need to draw rays not wavefronts
if wave slows down it bends towards the NORMAL
That means the angle of refraction is smaller than the angle of incidence
if speed decreases, wavelength also does, while frequency stays constant
when light exits it speeds up again and bends away from the NORMAL
Permanent magnets and induced magnets
Permanent magnets always produce a magnetic field, where as induced magnets become magnetised when in another magnetic field
