Physics Practical Summaries

Core Physics I

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

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 ( $A = \pi r^2$ ) to get the resistivity

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 $y$ -intercept is the emf
The negative of the gradient is the internal resistance

Drop a ball of known diameter into a cylinder of liquid. Measure the time it takes to fall a marked distance
Stokes' law ( $F = 6\,\pi\,\eta\,r\,v$ ) 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

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 $l$
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

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)

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 $\frac{1}{f}$ against $\lambda$ . The gradient is the mass per unit length
Use the equation $f = \frac{1}{2l} \times \sqrt{\frac{T}{\mu}}$

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
$\theta = tan^{-1}($ distance between dots $\div$ distance from laser to wall $)$
$\lambda =$ distance from laser to wall $\times sin\,\theta$

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. $m_{\mathrm{system}} =$ trolley mass $+$ hanging mass
Release the trolley from the top. Use the change in velocity from the light gates in $\Delta p_{\mathrm{system}} = m_{\mathrm{system}} \Delta v$
Divide this by the time between the two light gates ( $\Delta t$ )
Calculate total force with $F = Mg$ ( $M$ is the hanging mass)
Do repeats, and vary the hanging mass
Plot $F$ against $\Delta p_{\mathrm{system}}$
If it's a straight line, $\Delta p = F\Delta t$

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 $x$ and in $y$ . Multiply each by the framerate to get the velocity in that direction
The total momentum before and after the collision should be equal

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)