Physics Flashcards
(30 cards)
RPA : Specific Heat Capacity RPA
Summary
Investigation to determine the
specific heat capacity of one or
more materials.
The investigation will involve linking
the decrease of one energy store
(or work done) to the increase in
temperature and subsequent
increase in thermal energy stored
Equipment List
* copper block wrapped in insulation, with two holes for a thermometer and
heater
* thermometer
* pipette to put water in the thermometer hole
* 30 W heater
* 12 V power supply
* insulation to wrap around the blocks
* ammeter and voltmeter
* five 4 mm leads
* stop watch or stop clock
* balance.
Method
#1. Measure and record the mass of the copper block in kg.
2. Place a heater in the larger hole in the block.
3. Connect the ammeter, power pack and heater in series.
4. Connect the voltmeter across the power pack.
5. Use the pipette to put a small amount of water in the other hole.
6. Put the thermometer in this hole.
7. Switch the power pack to 12 V. Switch it on.
8. Record the ammeter and voltmeter readings. These
shouldn’t change during the experiment.
9. Measure the temperature and switch on the stop clock.
10. Record the temperature every minute for 10 minutes.
11. Calculate the power of the heater in watts.
To do this, multiply the ammeter reading by the voltmeter
reading.
12. Calculate the work done by the heater. To do this,
multiply the time in seconds by the power of the heater.
13. Plot a graph of temperature in degrees against work done in J.
14. Draw a line of best fit. (Take care as the beginning of the
graph may be curved.)
15. Calculate the gradient of the straight part of your graph.
Repeat with a block of different materials
Formula:
SHC = (Power x Time) / (Mass x Temperature)
Variables
Independent - Material of the block
Dependent - Specific Heat Capacity of the Block
Control - The Surrounding temp, Temperature of the liquid and distance of the thermometer
RPA : Thermal Insulation RPA
Summary
Investigate the
effectiveness of different
materials as thermal
insulators and the factors
that may affect the
thermal insulation
properties of a material.
Investigation one
Investigating the effectiveness of different materials as thermal insulators
Equipment List
* large beaker eg 800 ml
* small beaker eg 250 ml
* thermometer
* kettle to heat water
* piece of cardboard
* scissors
* stop clock
* selection of insulating materials, eg polystyrene granules, sawdust, bubble wrap, newspaper.
Method
1. Use the kettle to boil water. Put 80 ml of this hot water into a small beaker.
2. Put the small beaker inside the large beaker.
3. Use a piece of cardboard as a lid for the large beaker. The cardboard must have a hole for the
thermometer.
4. Insert the thermometer through the hole in the cardboard lid so that its bulb is in the hot water.
5. Record the temperature of the water and start the stopwatch.
6. Record the temperature of the water every 5 minutes for 20 minutes.
7. Repeat steps 1‒6 using the different materials each time to fill the space between the small and large
beaker. Make sure you use the same volume of water each time.
8. Plot cooling curve graphs for each material with ‘Temperature in °C’ on the y-axis and ‘Time in minutes’
on the x-axis.
9. Use your graphs to determine which material is the best insulator.
Variables
Independent - Material Type
Dependent - Temperature change in water
Control - Surrounding Temperature, Starting temperatures, Thickness of materials
RPA : Resistance
Summary
Use circuit diagrams to set up
and check appropriate circuits
to investigate the factors
affecting the resistance of an
electrical circuit.
This should include: the length
of a wire (at constant
temperature); combinations of
resistors in series and parallel.
Equipment List
* a battery or suitable power supply
* ammeter or multimeter
* voltmeter or multimeter
* crocodile clips
* resistance wire eg constantan of different diameters attached to a metre ruler
* connecting leads.
Method
1. Connect the circuit.
It may be helpful to start at the positive side of the battery or power supply. This may be indicated by a
red socket.
2. Connect a lead from the red socket to the positive side of the ammeter.
3. Connect a lead from the negative side of the ammeter (this may be black) to the crocodile clip at the
zero end of the ruler.
4. Connect a lead from the other crocodile clip to the negative side of the battery.
The main loop of the circuit is now complete. Use this lead as a switch to disconnect the battery
between readings.
5. Connect a lead from the positive side of the voltmeter to the
crocodile clip the ammeter is connected to.
6. Connect a lead from the negative side of the voltmeter to
the other crocodile clip.
7. Record on a table the:
* length of the wire between the crocodile clips
* the readings on the ammeter
* the readings on the voltmeter.
8. Move the crocodile clip and record the new ammeter and
voltmeter readings. Note that the voltmeter reading may not
change. Repeat this to obtain several pairs of meter
readings for different lengths of wire
9. Calculate and record the resistance for each length of wire using the equation:
resistance in =
potential difference in V
current in A
10. Plot a graph with ‘Resistance in ’ on the y-axis and ‘Length of wire in cm’ on the x-axis.
11. You should be able to draw a straight line of best fit although it may not go through the origin.
Variables
Independent - Distance between crocodile clips
Dependent - Ammeter reading
Control - Same wire, Same Current, Same Battery
RPA : I-V Characteristics
Summary
Use circuit diagrams to
construct appropriate circuits to
investigate the I-V
characteristics of a variety of
circuit elements including a
filament lamp, a diode and a
resistor at constant temperature
Equipment List
* ammeter and milliammeter, or multimeter
* voltmeter or multimeter
* component holders
* 12 V, 24 W lamp eg a ray box lamp
* resistor
* diode and protective resistor (eg 10 Ω)
* rheostat eg 10 Ω, 5 A
* connecting leads.
Methods
ACTIVITY 1: The characteristic of a resistor
1. Connect the circuit. It may be helpful to start at the positive side
of the battery or power supply. This may be indicated by a red
socket.
2. Connect a lead from the red socket to the positive side of the
ammeter.
3. Connect a lead from the negative side of the ammeter (this
may be black) to one side of the resistor.
4. Connect a lead from the other side of the resistor to the
variable resistor.
5. Connect a lead from the other side of the variable resistor to
the negative side of the battery. The main loop of the circuit is
now complete. Use this lead as a switch to disconnect the
battery between readings.
6. Connect a lead from the positive side of the voltmeter to the side of the resistor the ammeter is
connected to.
7. Connect a lead from the negative side of the voltmeter to the other side of the resistor.
8. Record the readings on the ammeter and voltmeter in a suitable table.
9. Adjust the variable resistor and record the new ammeter and voltmeter readings. Repeat this to obtain
several pairs of readings.
10. Swap the connections on the battery. Now the ammeter is connected to the negative terminal and
variable resistor to the positive terminal.
The readings on the ammeter and voltmeter should now be negative.
11. Continue to record pairs of readings of current and potential difference with the battery reversed.
12. Plot a graph with ‘Current in A’ on the y-axis and ‘Potential difference in V’ on the x-axis. As the
readings include negative values the origin of your graph will be in the middle of the graph paper.
13. You should be able to draw a straight line of best fit through the origin. This is the characteristic of a
resistor.
Variables
Independent - Variable Resistor
Dependent - Potential difference
Control - Battery type, Ammeter and voltmeter
RPA : Density (Regular shape)
Summary
Use appropriate apparatus to make and record the
measurements needed to determine the densities of regular
and irregular solid objects and liquids.
Volume should be determined from the dimensions of
regularly shaped objects and by a displacement technique
for irregularly shaped objects.
Dimensions to be measured using appropriate apparatus
such as a ruler, micrometer or Vernier calipers
Regular Shaped object
Equipment List
* 30 cm ruler marked off in mm
* digital balance
* regular shaped objects.
Method
1. For each object measure the length, width and height.
2. Record your results in a table, including columns for volume, mass, density and substance.
3. Measure the mass of each object using the digital balance. Record the results.
4. Calculate and record the volumes (length width height).
5. Calculate and record the densities (mass ÷ volume).
6. Use the table below to identify the substance each object is made from.
Variables
Independent -
Dependent -
Control -
RPA : Density (Irregular Shape)
Equipment List
* digital balance
* displacement can and something to stand it on (eg a brick)
* various measuring cylinders
* beaker of water and an extra empty beaker
* paper towels
* cotton or thin string
* irregularly shaped object
Method
1. Measure the mass of one of the irregular shaped objects.
2. Record your results in a table, including columns for volume,
mass, density and substance.
3. Place a displacement can on a brick. Put an empty beaker
under the spout and fill the can with water. Water should be dripping from the spout.
4. Wait until the water stops dripping. Then place a measuring cylinder under the spout instead of the
beaker. Choose the measuring cylinder you think will give the most precise reading.
5. Tie the object to a piece of cotton. Very carefully lower it into the displacement can so that it is
completely submerged. Collect all of the water that comes out of the spout in the measuring cylinder.
6. Measure and record the volume of the collected water. This volume is equal to the volume of the
object.
7. Calculate and record the density of the object. Try to find out what substance it is made from.
8. Repeat steps 1‒7 for some other objects. Remember to refill the can each time.
Variables
Independent - Object Type
Dependent - Amount of Water Displaced
Control - Water Amount
RPA : Density (Liquid)
Equipment List
* digital balance
* 250 ml beaker
* 100 ml measuring cylinder
* suitable liquid eg sugar solution.
Method
1. Measure the mass of the empty beaker.
2. Record your results in a table. Your table will need columns for the:
* mass of the empty beaker
* mass of the beaker with the liquid in
* mass of the liquid
* volume of the liquid
* density of the liquid.
3. Pour about 100 ml of liquid into the measuring cylinder. Measure and record the volume.
4. Pour this liquid into the beaker. Measure and record the mass of the beaker and liquid.
5. Calculate and record the volume of the liquid.
6. Calculate the density of the liquid.
7. The density of water is 1 g/cm3
.
8. Determine the mass of sugar per cm3 dissolved in the water. Assume the sugar does not affect the
volume of the water.
Variables
Independent - Liquid Type
Dependent - Density of the Liquid - Density of the water
Control - Water Amount, Amount of sugar and beaker weight
RPA : Force and Extension
Equipment List
* a spring
* a metre ruler
* a splint and tape to act as a pointer
* a 10 N weight stack
* a clamp stand, with two clamps and bosses
* a heavy weight to prevent the apparatus tipping over
* a mystery object to weigh.
Method
1. Attach the two clamps to the clamp stand using the bosses. The top clamp
should be further out than the lower one.
2. Place the clamp stand near the edge of a bench. The ends of the clamps
need to stick out beyond the bench.
3. Place a heavy weight on the base of the clamp stand to stop the clamp stand
tipping over.
4. Hang the spring from the top clamp.
5. Attach the ruler to the bottom clamp with the zero on the scale at the top of
the ruler. If there are two scales going in opposite directions you will have to
remember to read the one that increases going down.
6. Adjust the ruler so that it is vertical. The zero on the scale needs to be at the
same height as the top of the spring.
7. Attach the splint securely to the bottom of the spring. Make sure that the splint is horizontal and that it
rests against the scale of the ruler.
8. Take a reading on the ruler – this is the length of the unstretched spring.
9. Carefully hook the base of the weight stack onto the bottom of the spring. This weighs 1.0N.
10. Take a reading on the ruler – this is the length of the spring when a force of 1.0 N is applied to it.
11. Add further weights. Measure the length of the spring each time.
12. You will need to find the extension of the spring (the amount the string has stretched). To calculate this
you subtract the length of the unstretched spring from each of your length readings.
13. Plot a graph with ‘Extension of spring in cm’ on the y-axis and ‘Weight in N’ on the x-axis.
14. Hang the unknown object on the spring. Measure the extension and use your graph to determine the
object’s weight. Check it with a newtonmeter
Variables
Independent - Amount of Weight Attached
Dependent - Extension of the spring
Control - Same spring.
RPA : Light
Equipment List
* ray box
* suitable power supply
* a slit and lens that fit the ray box and can be used to make a
narrow ray
* two rectangular transparent blocks of different materials (e.g.
glass, Perspex)
* 30 cm ruler
* protractor
* sheets of plain A3 paper.
Method
1. Set up the ray box, slit and lens so that a narrow ray of light is produced. Then
darken the room.
2. The ray box will get hot – be careful when you move it. Switch it off when you
don’t need it.
3. Place the ruler near the middle of the A3 paper and draw a straight line parallel
to its long side.
4. Use the protractor to draw a second line at right angles to this line. Label this
line with an ‘N’ for ‘normal’.
5. Place the longest side of a transparent block against the first line, with the
largest face of the block on the paper. The normal should be near the middle of
the block.
6. Draw around the transparent block. Be careful not to move it.
7. Use the ray box to direct a ray of light at the point where the normal meets the block. This is called the
‘incident ray’.
8. The angle between the normal and the incident ray is called ‘the angle of incidence’. Move the ray
box or paper to change the angle of incidence. (You will probably have to do this with the room
darkened.) Do this until you see a clear ray reflected from the surface of the block and another clear ray
leaving the opposite face of the block.
9. Mark the path of the incident ray with a cross. If the ray is wide, make
sure the centre of the cross is in the centre of the ray.
10. Mark the path of the reflected ray with another cross.
11. Mark the path of the ray that leaves the block (the transmitted ray) with
two crosses. One cross needs to be near the block and the other cross
further away.
12. Switch on the room lights. Switch off the ray box and remove the block.
13. Draw the incident ray by drawing a line through your first cross to the
point where the normal meets the block.
14. Draw the reflected ray by drawing a line through your second cross to the
point where the normal meets the block.
15. Draw the transmitted ray by drawing a line through the two crosses on the
other side of the block to that side of the block. Label this point with a ‘P’.
16. Draw a line that represents the path of the transmitted ray through the block.
Do this by drawing a line from point P to the point where the normal meets the
block.
17. Use the protractor to measure:
a. the angle between the incident ray and normal − this is the angle of
incidence
b. the angle between the reflected ray and normal − this is the angle of
reflection
c. the angle between the ray inside the block and the normal − this is the angle of refraction.
18. Now repeat steps 3‒18 for the other transparent block. Place the other block on the A3 paper.
19. Line up the long side of the block as before.
20. If the block is not the same size as the first one, carefully draw around it without moving it.
21. Use your ray box to send in an incident ray along the same line as before. Again you may have to work
in a darkened room.
22. Look at the directions of the reflected and transmitted rays.
23. If they are not the same as before, mark their paths using crosses.
24. Remove the block, switch off the ray box, and switch on the room lights.
25. Draw in the reflected and refracted rays.
26. Measure the angle of reflection and the angle of refraction. Record them in your table.
27. Physics theory suggests that the angles of reflection should be the same, but the angles of refraction
should be different. How well do your results support this theory?
Variables
Independent - Transparent Blocks
Dependent - Angle of Refraction and Reflection
Control - Paper, Light source and other light sources
RPA : Acceleration
Equipment List-
* linear air track and gliders
* vacuum cleaner
* bench pulley, string and small weight stack eg 1 N in steps of 0.2 N
* card
* two clamp stands, with clamps and bosses
* two light gates, interface and computer
* Adhesive putty to attach the weights to the glider
Method
1. Place the air track on a bench and attach it to the vacuum cleaner, set on ‘blow’.
2. Place a glider on the air track and switch on the vacuum cleaner. The glider should lift up off the air
track and be free to move.
3. Adjust the legs of the air track so that the glider moves without touching and the air track is horizontal.
There are two separate adjustments to make. With the vacuum cleaner on:
* place the glider above the adjuster that tilts the air track from side to side. Adjust the length of
the leg until the glider does not touch the sides
* place the glider in the middle of the air track. Adjust the other leg until the glider does not move
when released.
4. Cut out a piece of card measuring 5 cm 10 cm. Put it in the groove on the glider. The long side
should be horizontal.
5. Clamp the two light gates horizontally. Position them above the air track so that the card passes
through them as the glider moves.
6. Connect the light gates to the interface and computer. Start the software for timing. You should have
the opportunity to choose acceleration using two light gates. Type in the length of the card (10 cm)
when asked by the computer.
7. Check the movement of the glider by gently pushing it along the track. The software needs to be on.
The acceleration should be close to zero. Switch
off the vacuum cleaner.
8. Attach the bench pulley to the end of the air track
away from the vacuum cleaner.
9. Tie a length of string to the glider. Pass the string
over the pulley and attach the weight stack to the
other end of the string. Make sure the string is
horizontal and is in line with the air track.
10. Switch on the vacuum cleaner. The glider should
accelerate through the light gates as the weight
falls to the ground.
11. If necessary, move the second light gate so that the glider passes through it before the weight hits the
ground. If the weight hits the ground too early, the glider will stop accelerating too early.
12. The first experiment will investigate how the acceleration depends upon the force. The force is
provided by the weight stack.
* Attach the full weight stack (1 N) to the end of the string.
* Switch on the software.
* Make sure the glider is in position and switch on the vacuum cleaner.
* The glider should accelerate through the light gates towards the bench pulley.
* Record the acceleration. Repeat.
* If the two values are not similar, repeat again.
* Record your readings in a table and calculate the mean.
13. Remove one weight (0.2 N) and attach that to the glider. This will keep the total mass constant. (The
weight stack is being accelerated too.)
14. Repeat the experiment for a force of 0.8N, 0.6N, 0.4N and 0.2N. Remember to attach each weight to
the glider as it is removed from the weight stack.
15. Plot a graph with ‘Acceleration in m/s2
’ on the y-axis and ‘Force in N’ on the x-axis
Variables
Independent - Amount of Weight on stack
Dependent - Acceleration of the glider
Control - Same glider, same vacuum and string
RPA : Waves (Ripple Tank)
Equipment List
* ripple tank plus accessories
* suitable low voltage power supply
* metre ruler.
Method
1. Set up the ripple tank. A large sheet of white card or
paper needs to be on the floor under the tank.
2. Pour water to a depth of about 5 mm into the tank.
3. Adjust the height of the wooden rod so that it just
touches the surface of the water.
4. Switch on both the overhead lamp and the electric
motor.
5. Adjust the speed of the motor. Low frequency water
waves need to be produced.
6. Adjust the height of the lamp. The pattern needs to be
clearly seen on the card on the floor.
7. Place a metre ruler at right angles to the waves shown in the pattern on the card.
Measure across as many waves as possible. Then divide that length by the number of waves. This
gives the wavelength of the waves.
8. Count the number of waves passing a point in the pattern over a given time (say 10 seconds).
Then divide the number of waves counted by 10. This gives the frequency of the waves.
9. Calculate speed of waves
Formula
wave speed = frequency x wavelength
Variables
Independent - Speed of the motor
Dependent - Waves Passing a point
Control - Water amount, Light sources
RPA : Waves (String)
Equipment List
* vibration generator
* suitable power supply (variable frequency)
* suitable string or elasticated cord
* set of 100 g masses and hanger
* set of 10 g masses and hanger
* wooden bridge
* pulley on a clamp.
Method
Method
1. Set up the apparatus as shown.
2. Switch on the vibration generator. The string (or elasticated cord) should start to vibrate.
3. A clear wave pattern needs to be seen. To do this, adjust the tension in the string or move the wooden
bridge to adjust the length of the string. The waves should look like they are stationary.
4. Use a metre ruler to measure across as many half wavelengths as possible (a half wavelength is one
loop). Then divide the total length by the number of half waves. Multiplying this number by two will give
the wavelength.
5. The frequency is the frequency of the power supply
Variables
Independent - Tension on the string
Dependent - Waves
Control - Same string, same Generator
RPA : Radiation and Absorption
Equipment List
* Leslie cube kettle
* infrared detector
* heat proof mat.
Method
1. Place the Leslie cube on to a heat proof mat.
2. Fill the cube with very hot water and replace the lid of the cube.
3. Use the detector to measure the amount of infrared radiated from each surface. Make sure that before
a reading is taken the detector is the same distance from each surface.
4. Draw a bar chart to show the amount of infrared radiated against the type of surface
Variables
Independent - Colour of the Wall
Dependent - IR reading
Control - Temperature of the water inside. Distance IR detector is from the block
Sources of Error + Solutions
Random errors are due to things you have no control over, such as a change in room temperature whilst you were collecting the results. Repeating your measurements and finding a mean will reduce the effect of random errors.
Systematic errors are due to problems with the equipment you used. For example, the balances you used may have been out by 0.1 g for every measurement.
Solution to Random
- Repeat the experiment
- Controlled Environment
- Keep conditions the same
Solutions to Systematic
- “Zero” your equipment
- Swap Equipment for more accurate equipment.
- Subtract the error from the final results.
Scalers and Vectors
Scaler
Mass, Temperature speed, energy distance and time.
All have magnitude with no Direction
Vectors
Displacement, weight, force, velocity, acceleration and momentum.
Includes the distance and the Direction travelled.
Contact and Non Contact Forces
Force
- A push or pull that acts on an object due to the interaction with another object
Forces are Vectors.
Contact Forces
- Two objects are physically touching.
- Friction
- Tension
- Air resistance
- Normal Contact Force Is the force applied in Weight to the surface it sits on.
Non Contact
- Physically separated
- Gravitiaonal force
- Electrostatic force
- Magnetic force
Gravity and Weight
Mass is the amount of matter that an object has in it.
Earths Gravity - 9.81N per KG of mass
Weight - Mass x Gravitational Force
Measured using Newton Meter
Longitude and Transverse Waves
All types of waves come under two categories : Longitude or transverse
All waves Transfer energy.
Transverse waves
- Transfer Kinetic Energy
- Oscillations are perpendicular to energy transfer
Longitudinal Wave
- Sound Waves
- Travel as particles move side to side
- Tight groups of particles = compressions, smaller amount = rarefactions
- Parrelle to the direction of the energy transfer
Wave travels not the object
Electro Magnetic Waves
Electromagnetic waves are transverse waves.
Transfer energy from source to the absorber
Order of Colours
- Red (Lowest Frequency, Long wavelengths)
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet (Higher Frequency, Shorter Wavelength)
Electromagnetic Spectrum
- Radio (Low Frequency Long Wavelength)
- Microwaves
- Infrared
- Visible Light (Only detected by eye)
- Ultra Violet
- X rays
- Gamma Rays (High Frequency, Short Wavelength)
Properties Of Wave
Amplitude is the maximum point from the “undisturbed” point in the wave.
Usually the peak or trough of the wave
*Wave Lenght** Point on one Wave to point on another wave.
Energy Stores and Systems
Conservation of energy
- Energy is never created or destroyed instead is transferred
whenever it is transferred the energy is stored in another object,
Energy stores
- Thermal energy
- Kinetic Energy
- Gravitational Potential energy
- Elastic Energy
- Chemical
- Magnetic
- Electrostatic
- Nuclear (Breaking atoms apart)
Energy transfer
- Mechanically
Physically doing something such as stretching an elastic band - Heating
Change in thermal temperature - Electrically
adding an electrical source - Radiation
E.g Light
Collection of matter is a System
- Open systems can transfer and interact with the outside world meaning can be lost to the outside
- closed system cannot be transferred to the outside world so is limited to remaining within side of the system
Kinetic Energy
Kinetic energy is the energy it possess due to its motion.
Anything moving has kinetic energy
amount depends on speed and mass of an object, More speed more energy. More mass more kinetic energy it has if everything else is kept the same.
formula : Kinetic Energy x 0.5x Mass x Velocity^2
1/2xmxv^2
Units : Joules
Gravitiaonal Protentional Energy
**Gravity **
Force of attraction between two objects is relative to the mass and how far apart they are from each other
Earths GFS is equal to 9.8N/Kg
Mass x Gravitational field strength = Weight
GPE = Mass x Gravitiaonal field strength x height
Specific Heat Capacity
Internal Energy is the total energy stored by particles making up a substance or system.
Kinetic Energy and Protentional Energy make up internal energy
Whenever heated the internal energy is increased
Some substances require more energy to raise the temp
**Amount of Energy of 1kg of a substance by 1 degree Celsius **
