practicals Flashcards
(15 cards)
Investigate the motion of everyday objects such as toy cars
- Attach the bench pulley to the end of a long bench.
- Secure the mass hanger to one end of the string and attach the other to the toy car
- pass the string over the bench pulley, and pull the car back so that the mass
hanger is just resting on the floor. - Mark the car’s position with masking tape - this is the end marker.
- Pull the car back so the mass hanger is raised and touches the pulley - mark the
car’s position with tape - this is the starting marker. - Use the tape measure to record the distance between the start and end markers.
- Release the car from the start marker and start the stop clock - stop timing when
the car reaches the end marker (this will be the same time that the mass hanger
reaches the ground). - Repeat the experiment 5 times and calculate an average time.
Investigate how Extension Varies with Applied Force
- Using the ruler, measure the initial length of the first spring when no force is applied.
- Set up the spring so it is hanging securely from the clamp stand.
○ You can also secure the ruler to the clamp stand to ensure it does not move at all
during the experiment. - Add one of the masses to the end of the spring and record the extension of the spring.
○ The extension is the difference between the new length and the initial length. - Continue adding masses and recording the extension each time.
- Plot a graph of force applied against the extension of the spring.
○ Force can be calculated from mass x gravitational field strength (i.e. 10 x the mass
hanging on the spring).
○ The gradient of the line of best fit will be the spring constant as .
Investigate how Insulating Materials can be Charged by Friction
(Physics only)
- Before beginning the experiment, ensure the plate of the electroscope is uncharged (you
can do this by touching it with your finger). The leaf should hang straight down next to the
stem. - Charge up either a perspex or polythene rod by rubbing it with a cloth.
○ The polythene rod should become negatively charged as the cloth deposits
electrons onto its surface.
○ The perspex rod should become positively charged as the cloth removes electrons
from its surface. - Hold the rod near the plate of the electroscope and the leaf should be repelled from the
stem, showing that the rod is charged.
The charge from the rod is transferred to the metal plate and travels down the stem and leaf of the
electroscope. The stem and leaf therefore carry the same charge and repel each other.
Investigate the Refraction of Light using Rectangular Blocks,
Semi-Circular Blocks and Triangular Prisms
Place the glass block on a sheet of paper, and carefully draw around the rectangular perspex block using a pencil
Switch on the ray box and direct a beam of light at the side face of the block
Mark on the paper:
A point on the ray close to the ray box
The point where the ray enters the block
The point where the ray exits the block
A point on the exit light ray which is a distance of about 5 cm away from the block
Draw a dashed line normal (at right angles) to the outline of the block where the points are
Remove the block and join the points marked with three straight lines
Replace the block within its outline and repeat the above process for a ray striking the block at a different angle
Repeat the procedure for each shape of perspex block (prism and semi-circular)
Investigate the Refractive Index of Glass Using a Glass Block
Place the glass block on a sheet of paper, and carefully draw around the block using a pencil
Draw a dashed line normal (at right angles) to the outline of the block
Use a protractor to measure the angles of incidence to be studied and mark these lines on the paper
Switch on the ray box and direct a beam of light at the side face of the block at the first angle to be investigated
Mark on the paper:
A point on the ray close to the ray box
The point where the ray enters the block
The point where the ray exits the block
A point on the exit light ray which is a distance of about 5 cm away from the block
Remove the block and join the points marked with three straight lines
Replace the block within its outline and repeat the above process for a rays striking the block at the next angle
Investigate the Speed of Sound in Air (Physics Only)
Use the trundle wheel to measure a distance of 100 m between two people
One of the people should have two wooden blocks, which they will bang together above their head to generate sound waves
The second person should have a stopwatch which they start when they see the first person banging the blocks together and stop when they hear the sound
This should be repeated several times and an average taken for the time travelled by the sound waves
Repeat this experiment for various distances, e.g. 120 m, 140 m, 160 m, 180 m
Investigate the Frequency of a Sound Wave Using an Oscilloscope
(Physics Only)
- Connect the microphone to the oscilloscope and check that waveforms are produced when
sounds are made. You may need to alter the oscilloscope settings to ensure that the wave
forms fill the screen and are clear. - Make a sound using an instrument or by humming a note, and then press the hold button
on the oscilloscope so that the wave-form produced is frozen. - Measure the distance between two peaks, and then by referring to the time base, calculate
the length of time between the peaks. - This time is the time taken for one wave to be produced and is known as the time period.
- To calculate the frequency of the wave, use: f =1/T.
investigate energy transfer by conduction
Attach ball bearings to the ends of each metal strip at an equal distance from the centre, using a small amount of wax
The strips should then be turned upside down and the centre heated gently using a bunsen burner so that each of the strips is heated at the central point where they meet
When the heat is conducted along to the ball bearing, the wax will melt and the ball bearing will drop
Time how long this takes for each of the strips and record in a table
Repeat the experiment and calculate an average of each time
investigate energy transfer by convection
Fill the beaker with cold water (not too full) and place it on top of a tripod and heatproof mat
Pick up the crystal using forceps and drop it into the centre of the beaker – do this carefully to ensure the crystal does not dissolve prematurely
Heat the beaker using the Bunsen burner and record observations
Repeat experiment with hot water and record observations
investigate energy transfer by radiation
Set up the four identical flasks painted in different colours: black, grey, white and silver
Fill the flasks with hot water, ensuring the measurements start from the same initial temperature
Note the starting temperature, then measure the temperatures at regular intervals, e.g. every 30 seconds for 10 minutes
investigate density using direct measurements of mass and volume
irregular object:
Place the object on a digital balance and note down its mass
Fill the eureka can with water up to a point just below the spout
Place an empty measuring cylinder below its spout
Carefully lower the object into the eureka can
Measure the volume of the displaced water in the measuring cylinder
Repeat these measurements and take an average before calculating the density
Obtain a Temperature-Time Graph to Show the Constant Temperature
During a Change of State (Physics only)
Place the ice cubes in the beaker (it should be about half full)
Place the thermometer in the beaker
Place the beaker on the tripod and gauze and slowly start to heat it using the bunsen burner
As the beaker is heated, take regular temperature measurements (e.g. at one minute intervals)
Continue this whilst the substance changes state (from solid to liquid)
Investigate the Specific Heat Capacity of Materials (Physics Only)
- Use the balance to determine the mass of the block (in case it is not exactly 1kg).
- Use the pipette to add a drop of water to the thermometer hole to improve thermal contact,
then measure the initial temperature of the block. - Switch on the power supply and determine the power of the heater (if not already known).
○ This can be done by using the ammeter and voltmeter to obtain values for the
current and potential difference and using the formula . = IVP - Ensuring the block is insulated to reduce heat loss, heat the block for 10 minutes, recording
the temperature every minute. - Plot a graph of temperature against the work done by the heater.
○ Find work done using the formula work done (J) = power (W) x time (s). - Take the gradient of the line of best fit and divide it by the mass of the block to find the
specific heat capacity.
investigate the magnetic field pattern for a permanent bar magnet and between two bar magnets
- Sprinkle some iron filings onto a sheet of paper.
- Place the permanent bar magnet onto the paper and the filings should move into the shape
of the magnetic field. - Repeat this with two permanent bar magnets placed a short distance apart.
○ Experiment with placing like poles and unlike poles facing each other
investigating the penetrating powers of different types of radiation
Connect the Geiger-Müller tube to the counter and, without any sources present, measure background radiation over a period of one minute
Repeat this three times, and take an average. Subtract this value from all subsequent readings.
Place a radioactive source a fixed distance of 3 cm away from the tube and take another reading of count rate over a period of one minute
Take a set of absorbers, i.e. some paper, several different thicknesses of aluminium (increasing in 0.5 mm intervals) and different thicknesses of lead
One at a time, place these absorbers between the source and the tube and take another reading of count rate over a period of one minute
Repeat the above experiment for other radioactive sources
