REQUIRED PRACTICALS Flashcards
(1) investigate the motion of everyday objects such as toy cars or tennis balls:
- mark a starting/ finishing line using tape
- measure the distance around the track using a trundle wheel/ tape measure
- start the stopwatch when the runner leaves the starting line and stop the stopwatch when the runner crosses the finish line
- make sure that the runner runs along the same part of the track that was measured
- have three different people run and find a mean time
- calculate average speed by using the equation average speed= distance of track/ mean time taken
(2) Investigate how extension varies with applied force for helical springs, metal wires and rubber bands:
(2) Investigate how extension varies with applied force for helical springs, metal wires and rubber bands: independent variable
force/ weight hanging from the spring
(2) Investigate how extension varies with applied force for helical springs, metal wires and rubber bands: dependent variable
extension of spring
(2) Investigate how extension varies with applied force for helical springs, metal wires and rubber bands: control variable
same spring, room temperature
(2) Investigate how extension varies with applied force for helical springs, metal wires and rubber bands:
- measure the initial length of the spring using a set square and ruler
- hang a 100g mass on the spring and measure the extended length
- measure the length at eye level to avoid parallax error
- calculate and record the weight using weight= mass x gravity
- calculate and record the extension using extended length - original length
- repeat steps using increasing masses 200g, 300g, 400g, 500g, 600g
- plot a graph of force/weight against extension
- If the graph is a straight line trough the origin, force is proportional to extension and the spring obeys Hooke’s law
(3) investigate how insulating materials can be charged with friction:
- charge a polythene rod by rubbing it with a cloth
- place the charged rod on a watch glass
- charge the second polythene rod by running it with a cloth
- place the second rod near the first rod on a watch glass
- the rods should repel one- another
(4) investigate the refraction of light using: rectangular blocks, semi-circular blocks, right-angled triangular prisms and equilateral triangular prisms:
- critical angle= sin c= 1/n
(5) investigate the refractive index of glass: independent variable:
angle of incidence
(5) investigate the refractive index of glass: dependent variable:
angle of refraction
(5) investigate the refractive index of glass:
- place a rectangular glass block on a piece of paper and trace around it with a pencil
- shine a ray of light from a ray box at a rectangular block
- trace the ray into and out of the block
- remove the block and draw the normal line where the ray entered using a protractor
- measure and record the incident angle
- vary the incident Angle and repeat
- calculate sin i and sin r
- plot a graph of sin i against sin r
- the gradient of the graph is the refractive index of the glass block
(6) investigate the speed of sound in air (with people):
- measure 100m using a tape measure or a trundle wheel
- at one end, have a person make a loud noise by banging two sticks together
- at the 100m mark, have a person time from when they see the two sticks hitting to when they hear the sound using a stopwatch
- repeat five times and calculate the mean time
- calculate the speed of sound by using average speed= 100m/ mean time
- be sure to wait until there is no wind before taking a reading
(6) investigate the speed of sound in air (with a microphone):
- place microphones 2 metres apart using a tape measure
- make a very loud/ sharp sound on the far side of microphone A
- microphone A will start the microsecond timer and microphones B will stop the microsecond timer
- record the time for the sound to travel from microphone A to microphone B
- repeat 5 times and find a mean time
- calculate the speed of sound by using speed= 2.00m/ mean time
(7) PAPER TWO ONLY investigate the frequency of a sound wave using an oscilloscope:
- connect the microphone to the oscilloscope using the leads
- create a steady sound using a speaker
- adjust the time base so that at least one complete wave is on the screen
- count the number of divisions for one complete wave (i.e. crest to crest)
- calculate the time period of the wave by multiplying the number of divisions for one wave by the time base
- calculate the frequency of the wave using f= 1/T
(8) investigate thermal energy transfer by conduction:
- a Bunsen burner heats up the end of a rod
- thermal energy is transferred via conduction
- the particles at the hot end of the rod vibrate more and transfer their energy by colliding with the particles next to them
- the thermal energy transfers from hot to cold
- this melts the wax and paper clips fall off
(8) investigate thermal energy transfer by convection:
- water above a Bunsen burner heats up
- the particles in the water gain kinetic energy and vibrate more, they move apart making hot water less dense
- the hot water rises
- the cold water is more dense and falls to replace the hot water
- this sets up a convection current
(8) investigate thermal energy transfer by radiation:
- Leslie cube- each side is painted a different colour o texture
- fill the container with hot water from a kettle and measure the temperature radiating from each surface using an infrared thermometer
- matt black surfaces radiate heat the best
(9) investigate density using direct measurements of mass and volume: regular object
1.measure the length of each side of the cuboid using a ruler
2. calculate volume using volume= length x width x height
3. measure the mass using a balance
4. make sure that the balance is zeroed before using
5. calculate density using density= mass/volume
(9) investigate density using direct measurements of mass and volume: irregular object
- measure the mass of object using a balance
- make sure that the balance is zeroed before using
- fill a measuring cylinder halfway with water
- record the initial volume of water at eye level and from the bottom of the meniscus
- lower the rock into the measuring cylinder and record the final volume
- calculate volume of the rock by taking the final volume of water - initial volume
- calculate density using density= mass/ volume
- may need to use a eureka can
(10) investigate the specific heat capacity of materials including water and some solids:
- measure and record the mass of the block using a balance- make sure that the balance is on zero before using it
- measure and record the initial temperature of the block using a thermometer
- turn on heater and at the same time start the stopwatch
- record the current and voltage supplied to the heater
- leave the heater on so that the block heats up by about 20 degrees celsius
- turn of the heater and stopwatch at the same time
- record the time and the final temperature of the block
- calculate the change in temperature of the block taking away the initial temperature from the final temperature
- calculate energy supplied using E= IVt
- calculate the specific heat capacity by using c= energy supplied/ mass x change in temp
(11) investigate the magnetic field pattern for a permanent bar magnet and between two bar magnets: iron filings
- place two magnets under a sheet of paper with opposite ends to each other
- sprinkle iron filings evenly around the paper
- tap the paper to get them to settle
(11) investigate the magnetic field pattern for a permanent bar magnet and between two bar magnets: plotting compasses
- place a magnet on top of paper and trace around it
- place compass at the corner of the north pole
- using a pencil, mark where the compass is pointing using a dot
- move the compass on top of the dot
- mark a dot where the compass is pointing
- repeat until you reach the south pole
- draw a sooth curve through the dots and draw an arrow on the magnetic field line in the direction that the compass was facing
- repeat for other magnetic field lines around the magnet
(12) investigate the penetration powers of different types of radiation using either radioactive sources or simulations:
- remove any sources from near the GM tube
- turn on the counter and record the number of counts in 10 minutes
- calculate the counts per second by number of counts/ 600s
(13) describe how current varies with voltage in wires, resistors, metal filament lamps and diodes and how to investigate this experimentally:
- vary the voltage across the component using a variable resistor
- record voltage across the component
- record current through the component
- repeat readings and find a mean
- turn off in between readings to control temperature
- plot a graph of current against voltage
- if a graph is a straight line through the origin, the component obeys Ohm’s law and is said to be Ohmic
(14) PAPER 2 ONLY obtain a temperature-time graph to show the constant temperature during a change of state:
- place stearic acid into a hot water bath
- remove from the hot water bath and place into a beaker of warm water
- start the stopwatch and record the temperature pf the stearic acid every minute until falls to 50 degrees celsius which is below the freezing temperature of stearic acid
- plot a graph to show temperature against time
