How do you investigate motion - first 3 stages?
- measure the ,ass of the trolley, unit masses and hanging hook
- measure the length of the piece of card which will interrupt that light gate beams
- adjust the height of the ramp until the trolley just starts to move
- mark a line at top of ramp so that trolley starts at the same point each time and travels the same distance
How do you investigate motion-last 3 steps?
- attach the trolley to the hanging mass and then let the trolley go so it rolls down the slope
- each light gate will record the time when the trolley passes through it and speed of it at that time
- (time between both, initial speed first light gate, final is second gate)
How do you investigate the trolley mass effect on acceleration?
Add masses one at a time to the trolley
- keeping the mass and the hook constant so the accelerating force on the trolley constant (these two multiplied together)
- repeat previous stages
How do you investigate the effect of the accelerating force?
Start with all the masses loaded onto the trolley and transfer the masses to the hook one at a time
-repeat previous stages each time you move a mass
You transfer the masses because you need to keep the mass of the whole system the same as the accelerating force caused both the trolley and hanging masses to accelerate
Effects of investigating motion?
- increasing accelerating force increase acceleration, they are directly proportional
- increasing the mass of the trolley decreases acceleration, they are inversely proportional
How do you measure the speed of sound in a solid?
- measure and record the length of a rod of metal
- set it up hanging from a clamp stand on elastic bands
- tap the rod with the hammer and write down the peak frequency displayed by the computers connected to the microphone at one end
- repeat and calculate an average
- calculate the speed, where wavelength is twice the length of rod
Who does investigating sound in a solid work?
Hitting the rod causes waves to be produced along the rod
- these make the rod vibrate and produce sound waves in the air around the rod
- these sound waves have the same frequencies as the waves in the rod
How do you measure waves in a liquid?
- measure the distance between wave fronts using a rule next to the ripple tank (photo might make this easier) and measure across 10 wavefronts, divide by 10
- Calculate how many wavefronts are produced in 30s (f = no. Of wavefronts/ 30)
- wavspeed = frequency x wavelength
-how do you measure refraction - first 3 stages?
- place a glass block on a piece of paper and trace around it
- draw a normal line at 90° to the surface of the block
- place the block back in its place
- use a ray box and slot to shine a single beam of light at the block
What are the last stages of measuring refraction?
- the ray will refract and leave and leave to block, so mark where it enters and leaves (draw normal for emergent ray)
- draw incident and emergent ray, join them up with internal ray
- use protractor to measure angle of incidence and refraction
- Repeat with different angles of incidence and draw a graph (angle of refraction on Y, angle of incidence on X)
How do you measure current and voltage for a fixed resort and filament lamp?
- set up circuit with the ammeter and resistor in series and voltmeter in parallel to the resistor
- set the power pack to 10V and then record the readings of ammeter and voltmeter
- adjust the slider on the variable resistor and repeat with different input powers
- repeat with filament land instead of resistor and plot an IV graph
What do you have to be aware of in first electricity experiment?
- be sure that the current doesn’t get too hot as this will mess up your results
- if it does disconnect for a while between reading do it can cool down
How do you measure how resistance varies in parallel?
- set up a series circuit with a resistor, ammeter and voltmeter, vary the output pd from power supply and record your readings
- replace the resistor with a filament lamp and repeat
- now connect a second filament lamp to the circuit in parallel and connect ammeter and voltmeters
- vary output PD and record results across each component
What are the results of the second electricity experiment?
- for series as the Pd increases the current through the resistor does (this is constant as fixed resistor), you should find a similar but non-linear relationship between p.d. And current for FL
- for parallel you should find as P.d increases so does current (across each bulb is same as input power)
- overall resistance is lower, so total current is greater than in series as V=IR
how do you calculate the specific heat capacity of water? - first stages
- use a mass balance to measure the mass of the insulating container
- fill the container with water and measure the mass again, difference in mass is the mass of the water in the container
- set up experiment with an electric immersion heater attached to a joule meter and thermometer in the water
- place lid on container
How do you measure specific heat capo it’s of water - last stages?
- when temp on thermometer has increased by a set amount drop the experiment and record the energy on the joule meter and the increase in temperature
- calculate the specific heat capacity of water through equation
- repeat and calculate and average
How do you calculate specific latent heat of water?
- fill a beaker with crushed ice
- place a thermometer into a beaker and record the temp of ice
- using a Bunsen burner gradually heat the beaker
- every twenty seconds record the temperature and the current state of the ice
- continue this process until the water begins to boil
- plot a graph of temperature against time for your experiment
What is good to note about specific latent experiment?
- when a substance is changing state, bonds are forming between particles which releases energy
- this means temperature doesn’t go down until all the substance has turned into a liquid or solid
- flat part on graph
How do you investigate elasticity?
- measure the natural length of the spring with no load applied with a ruler
- add a mass to the spring and allow the spring to come to rest
- record the mass and new length of the spring,extension is change in length
- repeat varying the mass and recording an average of each one
- plot a force extension graph, sheikhdom on,y start to curve if exceeded the limit of proportionality
What are controls in elasticity experiment?
- use identical spring as different materials have different spring constants and will bend more
- take measurements at eye level to make them more accurate
- work dome can be found by area under linear section of graph
How can you investigate the densities of solids and liquids?
- measure the mass of the object using a mass balance
- fill the displacement can with a liquid of unknown density
- drop the object on and collect the water displaced in a measuring cylinder
- measure volume of water displaced
- density = mass of object/ volume of water displaced
How do you measure density of solids and liquids using liquids?
- place a measuring cylinder on mass balance and record
- pour liquid in measuring cylinder and remeasure using a mass balance, mass of liquid is that minus the mass of cylinder
- measure volume of liquid
- density = mass/volume
What’s a top tip for measuring density if the object floats?
-gently push down on the object with a finger until it is just beneath the surface
how do you investigate the amount of thermal energy radiated and absorbed?
- wrap four identical test tubes with the same material but of a different surface (black, white paper, glossy and matte paper)
- boil the water in a kettle and fill each test tube with the same volume of water
- use a thermometer to measure the temp of water every minute, seal with bungs between measurements
