OCR GCE AS Level Physics A AS Paper 2 June 2022 question paper H156/02

A student investigates the motion of a steel ball in oil in a laboratory.

The radius r of the ball is 8.1 mm.

Describe how the student can determine r accurately in the laboratory.

The student uses a measuring cylinder and a digital balance to determine the density of the oil. The student records the following measurements:

• mass of empty measuring cylinder = 96 g

• volume of oil added to measuring cylinder = 87 cm³

• total mass of measuring cylinder and oil = 169 g

Show that the density of the oil is about 840 kg m^–3.

The steel ball is submerged in the oil.

Show that the upthrust acting on the steel ball is 1.8 × 10^–2 N.

Use the graph to calculate the velocity u of the steel ball at time t = 0.20 s.

=........ m s^–1 u

2* A student is investigating the motion of a trolley as it accelerates from rest along a horizontal surface. The diagram shows the trolley on a horizontal surface. A load of weight W accelerates the trolley.

Point P is a distance d from the initial position of the trolley. A light gate connected to a timer is used to determine the velocity v of the trolley at point P.

It is suggested that the relationship between v and the mass M of the trolley is

where Q and R are constants.

Describe, with the aid of a suitable diagram,

• how an experiment can be safely conducted to test this relationship between v and M, and,

• how the data can be analysed to determine Q and R.

The diagram shows a uniform rod which is in equilibrium. The rod has a circular cross-section and has length 0.600 m and weight 2.1 N.

Mass M is suspended at a distance of 0.100 m from point A. A weight of 0.49 N is suspended at a distance of 0.220 m from point B. A string is attached to the rod at a distance d from point A. The tension in the string, measured by the newton-meter (force meter), is 3.9 N.

Show that M is about 0.13 kg.

By taking moments about point A, determine d.

A ball of mass 0.16 kg is dropped from rest from a height of 2.5 m above the ground.

Assume air resistance is negligible.

Calculate

the change in gravitational energy E_p

E_p =........ J

Calculate

R

the kinetic energy E_k of the ball as it reaches the ground

the angle between the ground and the direction of the ball as it reaches the ground.

The table shows the refractive index of air, glass and oil for red light. It also shows the speed v red light in air.

Complete the table by determining the missing values for v for glass and oil. Write your answers to 3 significant figures.

The path of a ray of red light is shown entering the glass block.

Complete Fig. 5.1 to show the path of the ray through the block until it leaves the block.

The path of a ray of red light is shown entering the glass block.

Calculate the critical angle C for a ray of red light at the boundary between glass and oil.

Complete Fig. 5.2 to show the path of the ray through the block until it leaves the block.

A student is investigating electron diffraction. A beam of electrons is directed towards a thin slice of graphite in an evacuated tube.

The electrons are accelerated by a potential difference of 1800 V. The diagram below shows the pattern formed on the fluorescent screen of the evacuated tube.

Explain why this pattern is formed.

The relationship between the de Broglie wavelength and the accelerating potential difference V is

where m is the mass of the electron and e is the elementary charge.

Calculate the momentum p of an electron.

=........ kg m s^–1 p

An electric cooker has two independent heating rings A and B as shown in Fig. 7.1.

The cooker rings A and B are connected in parallel to a 230 V power supply. At maximum power, ring A has a power of 1100 W and ring B has a power of 1700 W.

Show that the maximum current in the cooker is less than 13 A.

The cost of 1 kW h of energy is 18p. Calculate the cost of using the cooker at maximum power for 30 minutes.

Complete Fig. 7.2 to show how the student should connect the circuit to determine the

resistance.

The current in the wire is 0.34 ± 0.02 A and the potential difference across the wire is 6.2 ± 0.2 V. Calculate the resistance R of the wire.

Calculate the percentage uncertainty in R.

Suggest why R from (c)(ii) is less than 31 .

Suggest two improvements to the student’s experiment to determine R experimentally.

8* In an experiment to investigate microwaves, a microwave detector D is placed 100.0 cm from a microwave transmitter T.

A thin metal sheet is placed parallel to the line joining T and D. Point R is at the bottom of the metal sheet. The perpendicular distance between this line and point R is y. The diagram shows the path of microwaves travelling directly from T to D and the path of microwaves from T reflected from R to D. There is a 180° phase change when microwaves are reflected at R.

The metal sheet is moved away from the line joining T and D so that y increases. The metal sheet remains parallel to the line from T and D. A series of maximum and minimum intensities are observed.

The table shows the values of y for successive maximum and minimum intensities.

Explain the presence of the regions of maximum and minimum intensities and determine the

wavelength of the microwaves.