O Level Physics 5054 Paper 21, Oct/Nov 2024

Calculate the combined mass of the trolley and block. combined mass = .................................................... kg

Fig. 1.1 shows that a student attaches a spring of spring constant $14\text{ N/m}$ to the front of the trolley. The student holds the trolley and block and stretches the spring. He releases the trolley and block. The trolley and block accelerate from rest. As the trolley and block accelerate, the student keeps the extension of the spring at $0.035\text{ m}$. Calculate the force exerted by the spring on the trolley. force = ..................................................... N

The trolley and block are pulled a distance of $0.86\text{ m}$ by the spring. Calculate the work done on the trolley. work done = ...................................................... J

Explain why the power transferred to the trolley and block increases as the speed increases.

Calculate the initial gravitational potential energy of the ball. gravitational potential energy = ...................................................... J

Calculate the speed of the ball immediately before the ball hits the ground. Ignore the effect of air resistance. speed = ................................................. m/s

When the ball hits the ground, it stops moving. The kinetic energy of the ball is transferred to internal energy. The temperature of the ball increases. The specific heat capacity of modelling clay is $1400\text{ J/(kg}{}^{\circ }\text{C)}$. Calculate the maximum possible temperature increase of the ball. Show your working. temperature increase = .................................................... ${}^{\circ }\text{C}$

Suggest one reason why the actual temperature increase of the ball may be smaller than the value calculated in (b)(i).

Explain, in terms of electrons and the atoms of the metal, how thermal energy is transferred through the walls of the metal cylinder.

The piston is fixed in position so the pressure of the gas increases as the temperature of the gas increases. State what happens to the motion of the particles of the gas as the temperature increases.

Explain, in terms of the particles of the gas, why the pressure the gas exerts on the walls of the metal cylinder increases as the temperature increases.

The gas in the cylinder reaches a temperature of $100{}^{\circ }\text{C}$. The piston is released and moves to the right. The temperature remains at $100{}^{\circ }\text{C}$. The pressure of the gas now decreases. Explain, in terms of the particles of the gas, why the pressure of the gas now decreases.

Eventually, the piston stops moving. Explain why.

Draw on Fig. 4.1 to show the paths of the red light and the violet light between the left-hand side of the prism and the screen at point R and point V.

State what these observations show about the change in speed of red light and change in speed of violet light as each enters the glass from the air.

Five other colours of light appear on the screen between the red light at point R and the violet light at point V. State the names of the five colours and list them in the correct order from red to violet. red ..................................................................................................................... violet

State how the frequency and the wavelength of the coloured light change going from red light to violet light. frequency .......................................................................................................................... wavelength ........................................................................................................................

On Fig. 4.1, point P is shown immediately next to point R. No light is observed at point P, but a detector at point P registers radiation reaching the detector. State which region of the electromagnetic spectrum is detected at point P.

Ultrasound waves cannot travel in a vacuum. Explain why.

Describe how a longitudinal wave differs from a transverse wave.

An ultrasound transmitter used for a medical scan produces an ultrasound wave of frequency $8.4\text{ MHz}$. In soft human tissue, ultrasound travels at $1500\text{ m/s}$. Calculate the wavelength of this ultrasound wave in soft human tissue. wavelength = ..................................................... m

The ultrasound wave passes from the soft tissue into bone where the speed of the ultrasound wave is greater than $1500\text{ m/s}$. State what happens to the frequency and to the wavelength of the ultrasound wave as it passes into the bone. frequency .......................................................................................................................... wavelength ........................................................................................................................

State a substance from which the bar magnet could be made.

The thin rod is perpendicular to the top and bottom surfaces of the bar magnet. Fig. 6.1 shows a view from above of the bar magnet with the N pole, the S pole and the thin rod labelled. Draw on Fig. 6.1 to show the pattern and the direction of the magnetic field around the bar magnet.

An electromagnet is switched on and a strong magnetic field is created around the bar magnet. Fig. 6.2 shows that the direction of the strong magnetic field due to the electromagnet is from left to right across the page. Draw arrows on Fig. 6.2 to show the direction of the horizontal forces that act on the poles of the bar magnet.

Describe and explain what happens to the bar magnet when the electromagnet is switched on.

Calculate: the current in the lamp current = ...................................................... A

Calculate: the resistance of the lamp in this circuit. resistance = ..................................................... $\mathrm{\Omega }$

A student has a battery of electromotive force (e.m.f.) $12\text{ V}$. The student uses the battery in a circuit with the $12\text{ V}$ filament lamp to obtain a range of suitable readings and plots the current–voltage graph for the lamp. Fig. 7.1 shows the battery and the filament lamp. On Fig. 7.1, complete the circuit diagram of a suitable circuit. You will need to add additional components.

On Fig. 7.2, draw the shape of the current–voltage graph for the filament lamp.

State what happens to the resistance of a filament lamp as the applied voltage increases and explain one reason for this happening.

Explain why hydrogen-3 cannot decay by the emission of alpha particles.

Hydrogen-3 decays by the emission of beta particles to an isotope of a different element. This element is represented in the equation by Q. Complete the nuclide equation for the decay of hydrogen-3. $${}_1^3\text{H}⟶\dots \dots \beta +\dots \dots \text{Q}$$

State the name of the element represented by Q.

The half-life of hydrogen-3 is 12 years. Define ‘half-life’.

A sample of hydrogen-3 is placed on a laboratory bench next to a Geiger-Müller tube and counter. The count rate is recorded at the same time on four successive days. Table 8.1 shows the count rates obtained. Table 8.1 State why the count rate decreases and increases.

State the name of the nuclear reaction that occurs at the centre of the star and describe this nuclear reaction.

Explain how this nuclear reaction helps to keep the star stable.

As a massive star approaches the end of its life, it stops being stable and becomes a red supergiant. State why the nuclear reaction can no longer keep the star stable.

Describe what then happens to the red supergiant.