Practise Edexcel A-Level Physics planning skills through apparatus choice, controlled variables, accurate measurement methods, repeats, uncertainty and safety.
A student is investigating the effect of temperature on the viscosity of oil by measuring how fast the oil flows through a funnel. He uses the apparatus shown.
State a piece of apparatus the student could use to vary the temperature of the oil.
State a piece of apparatus the student could use to measure the time taken for the oil to flow through the funnel.
The two thermometers shown below are available.
He chooses to use the digital thermometer.
Justify his choice.
Identify one control variable in this investigation.
Describe how this variable can be controlled.
The student initially measures the time from starting to pour the oil into the funnel to the last drop of oil falling from the funnel.
State how the rate of flow of the oil should be calculated.
Describe how the same apparatus could be used to calculate a more accurate value for the rate of flow of the oil.
A student made measurements on the solid metal prism shown.
The student used a balance to determine the mass of the metal prism.
The reading on the balance is shown below.
State the resolution of the balance.
The student used vernier calipers to determine the lengths a, b and c.
Explain one technique he should use to determine accurate values for these lengths.
A student investigated the motion of a small sphere on a curved track using the apparatus shown.
The student marked the track at the rest position of the sphere.
The student then marked the track at the start position of the sphere.
She used a metre rule to measure the horizontal distance d between the two marks on the track.
Describe an accurate method to measure a single value of d.
A student made measurements on the solid metal prism shown.
The student used a balance to determine the mass of the metal prism.
The reading on the balance is shown below.
State the resolution of the balance.
A student is investigating the effect of temperature on the viscosity of oil by measuring how fast the oil flows through a funnel. He uses the apparatus shown.
The student initially measures the time from starting to pour the oil into the funnel to the last drop of oil falling from the funnel.
Describe how the same apparatus could be used to calculate a more accurate value for the rate of flow of the oil.
A student investigated the bending of a plastic beam.
The beam, of width w and height h, was supported at either end by two metal rods a distance l apart, as shown.
She applied a force F to the middle of the plastic beam by hanging a mass from it.
The beam bent downwards as shown.
She measured the vertical distance d moved by the middle of the plastic beam and repeated this measurement for increasing values of F.
She recorded her results in a table, as shown.
The student suggested repeating the investigation using a glass rod instead of a plastic beam.
Explain a safety issue that would be caused by using a glass rod.
A student is investigating the effect of temperature on the viscosity of oil by measuring how fast the oil flows through a funnel. He uses the apparatus shown.
The student initially measures the time from starting to pour the oil into the funnel to the last drop of oil falling from the funnel.
State how the rate of flow of the oil should be calculated.
A student investigated the photoelectric effect using the apparatus shown.
He used a source of white light and colour filters to shine different wavelengths of light onto the photocell.
Photoelectrons were emitted with a range of kinetic energies, creating a small current in the photocell.
Using the potentiometer, the student varied the potential difference across the photocell. As the potential difference across the photocell increased, the current in the photocell decreased.
He measured the potential difference when the current in the photocell was zero.
He calculated the maximum kinetic energy of the photoelectrons for each wavelength of light.
The student's investigation involves a small random error and a large systematic error.
For each of these, suggest a source of the error and a realistic modification to the procedure which would reduce it.
Random error:
Systematic error:
When an object is in contact with a horizontal surface, there is a maximum frictional force F between the object and the surface before sliding occurs.
F is given by the equation
where is a constant and N is the normal contact force between the object and the surface.
A student investigated this relationship for a rubber block on a concrete surface. She set up the apparatus as shown in the diagram.
A tyre manufacturer carries out similar tests on samples of the rubber used for tyres.
Suggest why these tests are necessary.