Look inside the Edexcel A-Level Physics guide (9PH0)
Guide overview All 13 topics Sample questions Papers and weighting Look inside Questions and answers
Look inside the Edexcel A-Level Physics guide
Questions for a subtopic print together. The answers for that section print after them. Nothing else is in the file.
- Working as a Physicist82
- Mechanics180
- Electric Circuits148
- Materials101
- Waves and Particle Nature of Light288
- Further Mechanics98
- Electric and Magnetic Fields187
- Nuclear and Particle Physics120
- Thermodynamics96
- Space72
- Nuclear Radiation82
- Gravitational Fields62
- and 1 more
- Under what conditions may the equations of uniformly accelerated motion be used?
- State the equation of motion linking displacement, initial velocity, final velocity and time:
- State the equation of motion linking final velocity, initial velocity, acceleration and time:
- State the equation of motion giving displacement in terms of initial velocity, acceleration and time:
- State the equation of motion that does not contain time:
- Which equation of motion is most useful when time is neither given nor asked for?
- Why does s = (u + v)t/2 follow from the definition of average velocity when the acceleration is uniform?
- What sign convention should be used when analysing an object thrown vertically upwards?
- A car accelerates uniformly from rest at 2.5 m s⁻² for 8.0 s. What are its displacement and its final velocity?
- They apply only when the acceleration is constant in both magnitude and direction and the motion is along a straight line.
- The equation is s = (u + v)t/2.
- The equation is v = u + at.
- The equation is s = ut + ½at².
- The equation is v² = u² + 2as.
- v² = u² + 2as, because it links the two velocities, the acceleration and the displacement without involving time.
- For constant acceleration the average velocity is the mean of the initial and final velocities, and displacement is average velocity multiplied by time.
- One direction is chosen as positive and used throughout, so if upwards is taken as positive then the acceleration due to gravity is entered as negative.
- The displacement is s = ½ × 2.5 × 8.0² = 80 m and the final velocity is v = 2.5 × 8.0 = 20 m s⁻¹.
- A tennis ball of mass 0.058 kg leaves a racket at 45 m s⁻¹ from rest after a contact time of 5.0 ms. What average force acted on it?
- State the principle of conservation of linear momentum:
- How does conservation of momentum follow from Newton's third law?
- How is conservation of momentum applied to a collision that is not along a single line?
- Why can momenta in two dimensions not simply be added as magnitudes?
- A stationary object explodes into exactly two fragments. What can be said about their momenta?
- A snooker ball moving due east strikes an identical stationary ball and moves off at 30° north of east. What must be true of the second ball's motion?
- A 2.0 kg trolley moving north at 3.0 m s⁻¹ collides with a 1.0 kg trolley moving east at 6.0 m s⁻¹ and the two stick together. What is their speed afterwards?
- The change of momentum is 0.058 × 45 = 2.61 kg m s⁻¹, so the average force is 2.61 ÷ (5.0 × 10⁻³) = 522 N, or 520 N to 2 significant figures.
- The total linear momentum of a system stays constant provided no resultant external force acts on it.
- Two interacting bodies exert equal and opposite forces on each other for the same length of time, so they receive equal and opposite impulses and their momentum changes cancel exactly.
- Momentum is conserved independently in two perpendicular directions, so the momenta are resolved into components and the totals before and after are equated in each direction separately.
- Momentum is a vector, so only components along a common axis may be added arithmetically; otherwise vector addition is required.
- The two fragments must carry equal magnitudes of momentum in exactly opposite directions, so that the total remains zero.
- The second ball must gain a southward momentum component equal in size to the first ball's northward component, and the two eastward components must add up to the original momentum.
- The northward momentum is 6.0 kg m s⁻¹ and the eastward momentum is 6.0 kg m s⁻¹, giving a resultant of 8.5 kg m s⁻¹, so dividing by the combined mass of 3.0 kg gives 2.8 m s⁻¹ at 45° east of north.
- What is meant by the luminosity of a star?
- What is meant by the radiation intensity received from a star?
- State the equation relating the intensity received from a star to its luminosity and distance:
- Why does the distance appear as 4πd² in this relationship?
- What happens to the intensity received from a star if its distance from us were three times greater?
- A star of luminosity 3.9 × 10²⁶ W is 1.5 × 10¹¹ m away. What intensity is received?
- If the luminosity of a star and the intensity received from it are both known, how is its distance found?
- What two assumptions are made when using I = L/(4πd²) for a real star?
- It is the total radiant power the star emits in all directions, measured in watts.
- It is the radiant power arriving per unit area at the detector, measured in W m⁻².
- The equation is I = L/(4πd²), where d is the distance from the source.
- The emitted power spreads out uniformly over the surface of a sphere of radius d, and that sphere has area 4πd².
- The intensity would fall to one ninth of its value, because intensity is inversely proportional to the square of the distance.
- I = 3.9 × 10²⁶/(4π × (1.5 × 10¹¹)²) = 1.4 × 10³ W m⁻².
- Rearranging gives d = √(L/4πI).
- That the star radiates uniformly in all directions, and that no radiation is absorbed or scattered by dust and gas on the way to the observer.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
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Edexcel A-Level Physics Active Recall Guide
Every question paired with its answer, ready to work in three passes.