physics test revision exam

physics test revision exam

1. changing of state + slh

   • liquid
     • random pattern
     • atleast 50% are touching one another
     • can be poured
     • medium force of attraction
   • solid
     • organized
     • strong forces of attraction
     • vibrate on the spot
   • gas
     • move in a rapid, random motion
     • weak force of attraction
     • unorganized/ don't touch
   • changing state
     • melting: solid - liquid
     • evaporation: liquid - gas
     • freezing: liquid - solid
     • condensation: gas - liquid
     • sublimation: solid - gas
     • deposition: gas - solid
   • density formula's
     • d= m/v
     • v = m/d
     • m = d * v
   • specific latent heat
     • specific latent heat of fusion
       • --->
         • Is the amount of energy needed to change the state of 1kg of a substance from a solid to a liquid
     • specific latent heat of vaporisation
       • --->
         • is the amount of energy needed to change the state of 1kg of liquid into a gas.
     • e = m x l
       • m = e/l
       • l = e/m
   • heating/ cooling curves
     • straight lines = changing state
     • portrait line = increasing temperature

2. pressure + energy

   • equation
     • f= p /a
     • p = f x a
     • a = p / f
   • physics in balloons
     • inflating
       • the particles have no where to go so they collide with the wall of the balloon to create an exit with a large pressure.
     • constant size
       • a balloon stays the same size because particles on the other side of the balloon are trying to enter balancing the amount of pressure exerted on the balloon
     • deflates
       • the particles find an exit and escape the balloon this decreases the pressure exerted on the balloon
   • p1 v1 = p2 v2
     • pv = constant
   • insulation
     • best insulater = highest temperature in beaker
     • low temperature = heat into atmosphere
     • no insolation - so you can compare results
   • heat capacity
     • formula
       • Change in thermal energy = mass x specific heat capacity x temperature difference.
       • objects heat capacity
         • copper = 390 j/kg oc water = 4200 j/kg oc
         • mass = 1 kg
   • energy stores
     • elastic
       • stored in stretchy materials  e.g spring, elastic band elastic - gravitational potential
     • gravitational potential
       • The closer to the ground the less gravitational potential it has, e.g books, Gravitational - thermal when heated
     • magnetic
       • stored in a magnetic field, magnets
     • kinetic
       • affected by the objects mass and speed, e.g: bullet, plane, car
     • chemical
       • can be converted into other energy sources, e.g batteries, oil, coal, food
     • thermal
       • very hot, able to change an objects state, e.g lava
     • nuclear
       • is an energy found in nucleus' which is released when the atom splits, E.g: iranium, sun.
   • transferring stores
     • e.g sun: nuclear - thermal
     • e.g trampoline : elastic - kinetic
   • efficiency
     • efficiency = useful output energy transfer / total imput energy transfer.
     • e = u.o / t.i
     • u.o = e x t.i
     • t.i = u.o / e

3. energy resources

   • renewable
     • bio - fuel
       • Lower fuel prices, carbon neutral. Food shortages, fossil fuels needed for the fertilizer.
     • solar
       • small, portable, no pollution, renewable! depends on light intensity!
     • wind
       • low running costs, no pollution, renewable noisy, expensive, spoils view, depends on the wind!
     • hydroelectricity
       • Renewable, no pollution, no fuel costs, stored for when needed! expensive, large amount of land, ruin the environment! 
     • tidal
       • renewable, no pollution, reliable, cheap once built! expensive to build, can cause flooding, not strong enough waves!
     • Geothermal
       • renewable, no pollution, no environment damage! Expensive, few places were it works!
     • wave power
       • renewable, no pollution, uses lots of energy, expensive,
     • produce no pollution
   • non - renewable
     • oil
     • coal
     • gas
     • nuclear
     • heating, transport, electricity
     • cheap, reliable, concentrated
     • limited, produces greenhouse gasses

4. kinetic energy

   • Ek= 0.5 *m*v2
     • v= velocity
       • m/s
     • m= mass
       • kg
     • Ek = kinetic energy
       • j
     • m=ke/0.5 * v2
     • v2 = ke/ m*0.5

5. work done= force * distance

   • force = n
   • distance = m
   • work done = j
   • f = wd/ d
   • d= wd/ f

6. ep=m*g*h

   • ep= Gravitational potential energy
     • j
   • m = mass
     • kg
   • h = height
     • m
   • g= gravitational field strength
     • n/kg
   • g=ep/m*h
   • h=ep/m*g
   • g=ep/m*h

7. p=d*f/t

   • p=power
     • w
   • d= distance
     • m
   • f= force
     • n
   • t=time
     • seconds
   • d=p*f/t
   • f=p*d/t