RPs

Question 1

determining specific heat capacity of a 1kg block of material (RP1)

Answer 1

1) set up equipment, wrapping insulation around the base and sides of the block. the heater should fit snugly into one hole
2) if the thermometer has an air gap, drop water in using a pipette to increase thermal contact
3) if power is unknown use P = IV (measure current and potential)
4) keep power supply on and start the timer - measure temp. every 10 mins
5) plot a graph of temperature against work done by the heater

6) SHC = gradient divided by mass of block - mass is 1kg
so: inverse of gradient = SHC of block

Question 2

RP2: testing the effectiveness of different materials (and different thicknesses) as thermal insulators

Answer 2

Question 3

RP3: measure how resistance of a wire varies with length

Answer 3

set up this circuit - attach a length of wire along a metre rule using pieces of tape - attach a crocodile clip at 0cm on the ruler
attach another crocodile clip at 10cm on the ruler - and record both current and voltage through the wire
move crocodile clip 10cm further each time recording current and voltage
calculate resistance using V=IR
plot a graph of length against resistance

Question 4

RP3: measure resistance of a circuit

Answer 4

Question 5

RP4: investigating IV characteristics

Answer 5

construct the circuit.
set variable power supply or variable resister to lowest setting for potential difference
record I and V over the resister
increase current by 2V form power supply
change resistor to filament lamp, diode, etc
plot a graph of I against V for each component

Question 6

RP6: investigate relationship between force and extension

Answer 6

set up equipment
attach [pomter to base of spring, ensuring that it is parallel to the wrokbench, and perpendicular to the metre ruler - align the top of the ruler with top of the spring

measure initial length of spring (no weights attached)
add a 10g mass to the base of the spring and record the length.
repeat, continuing to add masses

calculate extension for each mass
convert all masses to weights
plot force against extension then calculate the gradientif the spring obeys Hooke’s Law, the graph of force against extension will be linear and pass through the origin

Question 7

RP7: investigating acceleration

Answer 7

Question 8

RP8: water waves in a ripple tank

Answer 8

Fill the ripple tank so the water has a depth of approximately 5mm. Place the ripple tank on top of a piece of white paper or card.
Place a wooden rod on the surface of the water and attach it to the low-voltage power supply and motor. Add a lamp to the circuit and hold the lamp above the ripple tank.
View the wave pattern from the side of the tank, looking through the water.
To measure the wavelength, place the metre ruler perpendicular to the wavefronts on the page. Measure across as many wavefronts as possible and divide by the number of waves.
To measure the frequency, count the number of waves passing a particular point in the wave tank over a given time (measure 10 or 20 seconds using a stop clock).
To calculate the wave speed, multiply the wavelength by the frequency.

Question 9

RP8: standing wave on a vibrating string

Answer 9

Question 10

RP9: investigating refraction

Answer 10

Question 11

RP10: investigating infrared radiation

Answer 11