Practicals Flashcards
Methods for measuring g.
- Drop object from known height and time how long it takes to fall. Repeat and average and use suvat to find g given the starting height and velocity and the time taken to fall.
- Set up a data logger to record time for the card to pass through the light gates and do suvat if the data logger doesn’t do it for you.
- Use a double interrupt card and do similar to the second experiment but record the distance between the gaps on the card.
Terminal velocity in a fluid.
work out the density of a viscous liquid in a long measuring cylinder using volume and mass. drop a ball bearing in the center of the liquid and use a stopwatch to time 2 seconds apart. Every two seconds mark where the ball is on the tube. Repeat in different colours and average the distance between the lines excluding outliers. Measure the distance between consecutive lines and work out the average velocity between each point. Plot a graph of velocity against time and draw a curve of best fit to determine when the ball reached terminal velocity and then plug into equation.
Determining the Young’s modulus of a material.
Work out diameter of wire at different points and average using micrometer to work out csa.
Measure original length from fixed end to a marked point on the wire. Use a long table for the experiment.(small load may need to be applied to keep wire taut).
Use masses of 100g and increase the load recording the extension each time and the force being applied.
After all the masses have been added calculate stress and strain and plot on a graph stress against strain.
Draw line of best fit and find gradient to find young’s modulus.
Electrical characteristics for ohmic and non ohmic components
Set up equipment and connect the component in series with an ammeter and a power supply.
Set up a voltmeter in parallel to the component and measure incremented p.ds of 1 V recording the current at each voltage in a table.
Plot the graph of current against potential difference and draw a line of best fit whether that is a curve or a straight line or both.
Determining the resistivity of a material.
Measure diameter of wire at different points using a micrometer and average to find csa
Set up a rheostat in series with a power supply with a voltmeter in parallel to the wire and an ammeter in series with the wire.
start the jockey at 50cm from the end and adjust the power supply so the voltmeter says 1 volt.
Measure the current and keep this constant through the experiment.
Decrease the length by 10cm each time and adjust the rheostat so the current stays constant and measure the p.d 3 times and average. Repeat for every interval and plot a graph of p.d against length and determine the gradient and use the equation to determine resistivity.
Determining the internal resistance of a cell
Connect a voltmeter in parallel to the cell and an ammeter in series with a variable resistor
Vary the resistance and record the current and voltage.
Plot these values on a voltage against current graph and use that to determine emf and internal resistance.
Young’s double slit.
Set up laser to shine through the slit and adjust the distance between the slits and a board.
Vary length of d and measure the slit separation by measuring multiple slits at once
plot d against a then use the equation to find the wavelength.
Finding Plancks constant.
Use the rheostat to adjust the potential difference across the LED until the LED turns off completely and repeat and average your results and plot V against 1/lambda. Then use equation to find h.
Finding Plancks constant.
Use the rheostat to adjust the potential difference across the LED until the LED turns off completely and repeat and average your results and plot V against 1/lambda. Then use equation to find h.
