Practical Skills I: Planning (Edexcel International A Level (IAL) Physics): Exam Questions

A student investigated the acceleration of a trolley as it rolled down a ramp. The trolley was released from rest at the top of the ramp and allowed to roll onto a horizontal surface. There was a single light gate above the horizontal surface, as shown.

The light gate was connected to a data logger. The data logger recorded the time taken for the card to pass through the light gate.

Describe how the student could determine the velocity v of the trolley as it passed through the light gate.

The student repeated the procedure and determined four values of v. The values are shown in the table.

 i) Calculate the mean value for v and the percentage uncertainty in v.

Mean v = ............................ m s^–1

Percentage uncertainty in v =........................... %

(3)

ii) The student measured the distance s that the trolley travelled on the ramp.

Determine the acceleration of the trolley on the ramp.

s = 1.50 m

Acceleration = ............................. m s^–2(2)

iii) A second student carried out the same experiment and determined a similar value for the acceleration of the trolley on the ramp.

State why this does not show that the results are reproducible.

(1)

A student was asked to investigate the ultimate tensile stress of a sample of thin nylon fishing line.

Describe a method to determine the maximum force the nylon fishing line can withstand before breaking.

Identify one safety issue with this investigation and how it may be dealt with.

Before testing, the student measured the diameter at five points along the sample of nylon fishing line.

i) Calculate the percentage uncertainty in the mean diameter of the nylon fishing line.

Percentage uncertainty = .........................................(3)

ii) The student read an article that suggested nylon fishing line can absorb water.

The article suggested that the ultimate tensile stress of nylon decreases by 10% after absorbing water.

She repeated her experiment, using new samples of fishing line before and after they absorbed water.

Evaluate whether her results support the suggestion in the article.

(5)

The specific latent heat of vaporisation L of water can be determined using the apparatus shown.

Devise a plan to determine the value of L using a graphical method.

You should include a circuit diagram and any additional apparatus required.

One significant source of error in this experiment is the uncertainty in the mass reading due to the water moving as it boils.

Explain how another significant source of error affects the value of L.

A student investigated how the current needed to melt a fuse wire depends on the diameter of the wire.

He connected each sample of fuse wire between two terminals separated by a fixed distance. The circuit contained a fixed power supply and additional components that enabled the student to vary and measure the current in the fuse wire.

Complete the diagram to show the circuit that the student should use.

Identify one safety issue with this investigation and how it may be dealt with.

The student needs to determine the current that melts the wire as precisely as possible.

Describe how the student should collect his data for one diameter of fuse wire.

For each diameter of fuse wire, the student repeated the procedure and recorded the mean melting current in a table.

Criticise the recording of the data.

A student investigated the motion of a paper cone falling through air.

The student released the cone from the same starting height and measured the time $t$ for the cone to fall between two markers. The markers were placed 1.50 m apart, as shown.

Describe how the student could use a metre rule to position the two markers on the wall 1.50 m apart as accurately as possible.

You may include additional apparatus.

The student assumed the cone was travelling at terminal velocity as it passed between the two markers.

Explain how the student could check this assumption.

The student repeated the measurement of $t$, as shown in the table.

(i) Determine the mean value of $t$.

[2]

(ii) Determine the percentage uncertainty in the mean value of $t$.

[2]

Another student suggests that using light gates connected to a data logger would give a more accurate value of $t$.

Discuss whether this suggestion is correct.