OCR GCE AS Level Physics A AS Paper 2 June 2025 question paper H156/02

A high speed passenger train is travelling at a velocity of 54 m s^–1. 1

The simplified graph shows the variation with time t of the velocity v of the train until it stops. At t = 0 the driver starts to think about applying the brakes.

Use the graph to determine the acceleration a of the train while the driver applies the brakes.

Use the graph to determine the total stopping distance d of the train from t = 0.

Suggest why the graph does not show the real motion of the train.

A student has six similar metal spherical balls. To determine the mean mass of a ball, the student measures the diameters of the balls.

The table shows the measurements.

The density of the metal is (8.9 ± 0.1) g cm^–3.

Show that the mean mass m of each of the balls is approximately 0.82 g.

Calculate the percentage uncertainty in m.

A hollow cylinder of mass 18 g has height 7.1 cm and cross-sectional area 6.2 cm². (b)

The six balls from part (a) are placed in the cylinder.

The cylinder is placed into a beaker of tap water. It floats upright as shown in the diagram.

The top of the cylinder is a distance x above the surface of the water.

The density of tap water is 1.0 g cm^–3.

Calculate x.

The student repeats the experiment using sea water.

State how the value of x changes.

Explain your answer.

To investigate mobile charge carriers, a student soaks a sheet of filter paper in a solution of salt. They fix metal conductors to the filter paper and connect the conductors to a power supply as shown in Fig. 3.1.

The student places two different soluble coloured crystals, Y and Z, on the middle of the filter paper as shown.

They close the switch.

After 20 s, due to the movement of the mobile charge carriers in crystals Y and Z, the filter paper appears as shown in Fig. 3.2.

On the filter paper shown in Fig. 3.2, draw an arrow to indicate the conventional current I for the

visible charge carriers of crystal Z. Label the arrow I.

Compare the visible charge carriers of crystal Y with the visible charge carriers of crystal Z.

Explain your answer.

A student sets up the circuit shown in Fig. 3.3.

The battery has an electromotive force (e.m.f.) of 4.8 V and negligible internal resistance.

The voltmeter measures the potential difference (p.d.) across the resistor of resistance 1.2 k

At a temperature of 20 C, the resistance of the thermistor is 2.6 k.

Calculate the voltmeter reading V.

The student places the thermistor in hot water.

At a temperature of 60 C, the voltmeter reads 3.2 V.

Calculate the resistance R of the thermistor.

The student replaces the resistor of resistance 1.2 k with a resistor of resistance 120 k.

Suggest why 120 k is not a sensible value to use to measure the temperature of a sample of water between 0 C and 100 C.

A student has a battery of electromotive force (e.m.f.) 2.2 V.

The quantities e.m.f. and potential difference (p.d.) are both measured in volts, V.

Describe one other similarity and one difference between e.m.f. and p.d.

A shopper pushes a trolley loaded with shopping at a constant speed of 0.75 m s^–1 along a horizontal surface as shown in Fig. 5.1.

The mass of the loaded trolley is 49 kg.

The force pushing the trolley is T.

The force of friction F_f between the trolley and the surface is 24 N.

On Fig. 5.2 draw a free-body diagram representing all the forces acting on the loaded trolley.

Label the forces.

State the value of T.

The shopper now pushes the loaded trolley up a slope made from the same surface, as shown in Fig. 5.3.

The angle between the horizontal and the slope is 8.6 and the trolley travels a distance of 2.4 m along the slope.

The force of friction F_f between the trolley and the surface is 24 N.

The equation relating power P to force F and velocity v is P = Fv.

Derive this equation from first principles.

Calculate the work done W against the force of gravity in moving the trolley along the slope.

Calculate the total power P needed to push the trolley up the slope at a constant speed of 0.75 m s^–1.

State the principle of conservation of momentum.

Glider R is stationary. Glider L moves at velocity u from left to right and collides with R. After the collision L rebounds and passes back through the light gate and R moves to the right.

The table records the time taken t for the card to pass through the light gate.

Determine the impulse of the force acting on R.

impulse =........ N s

Calculate the velocity v of R after the collision.

=........ m s^–1 v

The teacher changes one of the magnets to a cork and the other magnet to a pin and repeats the experiment.

Glider L moves from left to right. The time for the card to pass through the light gate is 0.26 s.

Glider L collides and sticks to glider R. After the collision L and R move together to the right.

Show, using energy considerations and the principle of conservation of momentum, that the collision is inelastic.

Include relevant calculations in your answer.

A laser emits green light of wavelength 5.32 × 10^–7 m.

The power of the laser is 1.0 mW.

Calculate the number of photons N emitted per second.

A student uses the laser to look at the interference pattern through a double slit.

The student arranges the apparatus as shown in Fig. 7.1.

Fig. 7.1 (not to scale)

The width of the screen is about 6 cm.

The distance between the double slit and the screen is 1.80 m.

The student determines that the fringe width is 3.82 ± 0.02 mm.

The light from the laser that falls on the double slit is coherent.

State the meaning of the term coherent.

Explain how the student determined the fringe width.

Calculate the separation a of the slits.

Give your answer to 3 significant figures.

Light from the laser is incident on an equilateral triangular glass prism as shown in Fig. 7.2.

The refracted ray in the prism is parallel to PQ.

The refractive index of the glass is 1.48.

Calculate:

the wavelength of the light in the glass

the angle of incidence i of the incident ray.