A Level Physics problem-solving questions
Browse free read-only PhysicsUK Solve examples for A Level Physics. Each preview shows the full problem, topic links and worked-solution guidance, with an option to try the question interactively.
4.4, 4.5
An optical sensor alternates between a green source of wavelength 520 nm and a red source of wavelength 650 nm. Treat each source as monochromatic and use its wavelength in a vacuum. Each source emits 2.0 μJ of light energy in a burst. Use c = 3.00 × 10⁸ m...
4.1, 4.2
A wearable warning indicator is connected to a supply that maintains 3.0 V across the indicator whenever it is on. During each 0.20 s pulse, a charge counter measures 0.012 C passing through it. Current is constant during a pulse and zero between pulses. The...
2.3, 3.2, 3.4
A sensor is suspended from a small ring by a light vertical cord. The ring is held by an inclined spring on its left and a light horizontal cord on its right, as shown in Figure 2. The spring slopes upwards to the left at 40.0° above the horizontal. The...
3.4, 3.2, 3.3, 3.1
A technician calibrates the spring bumper of a small instrument trolley. Figure 1 shows the force F needed to compress the spring by x from its natural length. The graph is a straight line through (0, 0), (0.020 m, 1.2 N), (0.040 m, 2.4 N) and (0.060 m, 3.6...
Thermal physics
A student investigates energy transfer between a hot metal block and a liquid. An aluminium block of mass $0.200\,\mathrm{kg}$ is heated from $20.0\,{}^\circ\mathrm{C}$ to $100.0\,{}^\circ\mathrm{C}$. The heater is then removed. The dry block is placed...
Forces
An athlete and racing wheelchair have a combined mass of $84.0\,\mathrm{kg}$. At the start of a straight training run, the wheelchair is already moving at $2.00\,\mathrm{m\,s^{-1}}$. For the next $1.50\,\mathrm{s}$, the athlete produces a constant forward...
Motion
During the final braking stage of a lunar landing, a lander is $48.0\,\mathrm{m}$ above the Moon's surface and moving vertically downwards at $12.0\,\mathrm{m\,s^{-1}}$. Its engines produce a constant resultant acceleration of $1.50\,\mathrm{m\,s^{-2}}$...
Thermal Physics
On a hot day, the air temperature in a sealed, well-insulated bedroom is 24 °C. To cool the room down, a person takes a solid block of ice from the freezer, places it directly in front of an electric fan, and closes the door. The room measures 5.0 m × 4.0 m...
Particles and radiation, Particles
A researcher is investigating the properties of a specific isotope of Lithium, ${}^{7}_{3}\text{Li}$. (a) Calculate the specific charge of the nucleus of a ${}^{7}_{3}\text{Li}$ atom. Give your answer in $\text{C kg}^{-1}$ to an appropriate number of...
Circular Motion, Gravitational Fields
Two identical stars, each of mass m, orbit their common centre of mass in circular orbits of radius r. The stars are separated by a distance 2r. Their orbital period is T. (a) Write down an expression for the gravitational force between the two stars. (1)...
Forces and Motion, Energy & Power
A lift of total mass 6.0 × 10² kg is accelerated vertically upwards from rest by a cable tension of 6.6 × 10³ N. (a) Calculate the acceleration of the lift. (3) (b) The lift reaches a constant speed of 3.0 m s⁻¹. Calculate the power output of the motor when...
Astrophysics
The Sun has absolute magnitude +4.8 and surface temperature 5800 K. A distant star has absolute magnitude −4.2 and surface temperature 3500 K. (a) Calculate the difference in absolute magnitude and hence the ratio of the luminosities of the two stars. [2]...
Materials
A spring obeys Hooke's law and has a spring constant of 25 N m⁻¹. (a) Calculate the extension produced by a force of 5.0 N. (2) (b) Calculate the elastic potential energy stored in the spring at this extension. (2)
Forces and Motion, Energy & Power, Materials
A testing rig uses a heavy block of mass $M = 12.0\text{ kg}$ to calibrate a vertical safety spring. The block is initially held at rest against the top of the spring. When released, the block compresses the spring. (a) The block is released from rest and...
Waves, Oscillations, Thermal Physics
A specialized acoustic sensor consists of a small metal sphere of mass $m = 1.20 \times 10^{-2}\text{ kg}$ suspended by a spring. When the sphere is displaced and released, it undergoes simple harmonic motion (SHM). An engineer uses an oscilloscope to...
Forces and Motion, Circular Motion, Oscillations
A small robotic probe of mass $m = 0.450\text{ kg}$ is designed to test the surface of a low-gravity asteroid. The probe is launched horizontally from the top of a vertical cliff of height $H = 12.0\text{ m}$ with an initial speed $u$. (a) On this asteroid,...
Waves
A student uses a signal generator to produce a sound wave in a laboratory. The signal is monitored using a cathode-ray oscilloscope (CRO). The trace on the screen shows a clear sinusoidal wave. The time-base of the CRO is set to $250\text{ }\mu\text{s...
Nuclear Physics
A researcher is investigating the properties of a specific isotope of Gold, $^{197}_{79}\text{Au}$. In a scattering experiment, alpha particles ($^{4}_{2}\text{He}$) are fired at a thin gold foil. (a) Calculate the radius of a $^{197}_{79}\text{Au}$ nucleus....
Gravitational Fields, Nuclear Physics
A hypothetical "Nuclear Star" is a dense, spherical object composed entirely of neutrons. It has a radius $R$ of $12.0\text{ km}$ and a uniform density equal to that of an atomic nucleus, $\rho = 2.30 \times 10^{17}\text{ kg m}^{-3}$. (a) Show that the mass...
Waves
A student uses a signal generator to produce a sound wave in a laboratory. The wave is detected by a microphone connected to an oscilloscope. The oscilloscope screen shows a trace of the wave with the time-base set to $50\text{ \mu s cm}^{-1}$ and the...
Forces and Motion
A high-speed "smart-sled" is tested on a horizontal track for emergency braking systems. The sled, initially travelling at a constant velocity $u$, passes a sensor at $t = 0$. At this instant, the braking system is engaged. The velocity $v$ of the sled as a...