Physics Practical Summaries
- This is old - I made these notes so I could prepare for the mock.
Please use the four separate pages for Core and Advanced Physics instead.
Core Physics I
CP 1 Determining the acceleration of a freely falling object:
- Drop a flat object through two light gates. Vary the distance between them
- Plot distance against time squared. Multiply the gradient by 2 to get the acceleration due to gravity
CP 2 Determining the resistivity of a wire:
- Measure the diameter in several places with a micrometer and find the mean
- Measure the current and pd for several different lengths
- Plot resistance against length (should be through origin)
- Multiply the gradient by the cross sectional area () to get the resistivity
CP 3 Finding internal resistance and emf:
- Connect a fixed resistor and a cell (or a potato). Add an ammeter in series and voltmeter in parallel
- Take readings with different resistors
- Plot pd against current. It should have a negative gradient
- The -intercept is the emf
- The negative of the gradient is the internal resistance
Core Physics II
CP 4 Finding the viscosity of a liquid:
- Drop a ball of known diameter into a cylinder of liquid. Measure the time it takes to fall a marked distance
- Stokes' law () can now be used to calculate the viscosity of the liquid
- Multiple balls of different diameters could be used to improve the results as there will be a large uncertainty in time measurements
CP 5 Finding the Young modulus of a material:
- Clamp a long copper wire inside some wooden blocks. The other end should go over a pulley attached to a mass
- Measure its diameter in several places and calculate the mean
- Attack a paper marker to the wire, over a ruler
- Record the distance between the marker and clamped end. This is
- Increase the weight and record the mass and difference between the base length and current one
- Calculate stress and strain
- Plot a stress-strain graph through the origin
- The Young Modulus is the gradient
CP 6 Calculating the speed of sound in air:
- Connect a microphone and signal generator to an oscilloscope as inputs
- Connect a speaker to the same signal generator
- Move the microphone until the waves are in phase. Record this distance. Keep doing this, moving the microphone further away
- Find the mean of the distances between each pair of readings. Multiply this by the frequency (from the signal generator, or the oscilloscope for greater accuracy)
CP 7 The effects of length/tension/mass per unit length on a vibrating string:
- Use a signal generator and vibration generator to vibrate a string connected to a mass through a pulley
- You can modify the length, tension or mass per unit length. Then adjust the frequency until one wavelength of a standing wave is formed
- Plot a graph of against . The gradient is the mass per unit length
- Use the equation
CP 8 Using a diffraction grating to calculate the wavelength of a laser:
- Put a diffraction grating over a laser. Clamp this a set distance from a wall
- Measure the distance between the zero order (centre) and first order dots (each side of the central one). Take the mean between these two readings
- distance between dots distance from laser to wall
- distance from laser to wall
Advanced Physics I
CP 9 Proving :
- Create a surface for a trolley. Compensate for friction. (or use an air track)
- Set up two light gates. Connect the trolley to a hanging mass with a pulley and string. trolley mass hanging mass
- Release the trolley from the top. Use the change in velocity from the light gates in
- Divide this by the time between the two light gates ()
- Calculate total force with ( is the hanging mass)
- Do repeats, and vary the hanging mass
- Plot against
- If it's a straight line,
CP 10 Analysing collisions between small spheres:
- Roll a sphere into another, whilst recording with a video camera. Put rulers on the table in view of the camera
- Use software to find the distance travelled each frame, in and in . Multiply each by the framerate to get the velocity in that direction
- The total momentum before and after the collision should be equal
CP 11 Analysing capacitor charging and discharging:
- Connect a CRO to a capacitor-resistor circuit (in parallel)
- Set the timebase to 0 so there's a dot rather than a wave
- Use a timer (with lap function) to record the time it takes to fall/rise one division for an entire charge/discharge
- Plot a V-t graph
- (or use a data logger, ammeter and voltmeter)