Space, Time and Motion | OCR A-Level Physics B (Advancing Physics) (H557)

Space, Time and Motion

204 questions
14 subtopics
The physics content, examined on all three papers
Component 01, Component 02 and Component 03

Space, Time and Motion is examined in all three written papers — the specification states that Components 01, 02 and 03 each assess content from across all the teaching modules, so nothing is confined to one paper.

It covers scalars, vectors and their representation, Resolving and adding vectors, Describing motion: displacement, velocity and acceleration, motion graphs, the kinematic equations for constant acceleration, Projectiles and motion in two dimensions, measuring motion in the laboratory, Determining the acceleration of free fall, newton's laws of motion, terminal velocity and resistive forces, momentum and impulse, conservation of momentum and collisions, work, energy and its conservation and power and modelling motion in small time steps.

Sample questions from Space, Time and Motion

Answer each one closed book first, then open the answer.

Scalars, vectors and their representation

Define velocity.

Show the answer
Velocity is the rate of change of displacement, and it is a vector pointing in the direction of that change.
Resolving and adding vectors

A box is pulled along the floor by a rope at 25° to the horizontal with a tension of 120 N. What is the component of the tension pulling the box forwards?

Show the answer
The forward component is 120 cos 25° = 109 N.
Motion graphs

How is the instantaneous velocity found from a curved displacement–time graph?

Show the answer
It is the gradient of the tangent drawn to the curve at that instant.
The kinematic equations for constant acceleration

A stone is thrown vertically upwards from ground level at 12 m s⁻¹. Taking g as 9.81 m s⁻², calculate the total time before it returns to the ground.

Show the answer
The time to the top is 12/9.81 = 1.22 s, so the whole flight lasts 2.4 s.
Measuring motion in the laboratory

Why is a ticker timer less suitable than a light gate for measuring fast motion?

Show the answer
At high speed the dots are widely spaced so few are printed, giving little data, and dragging the tape adds appreciable friction.
Determining the acceleration of free fall

How can video analysis give the acceleration of free fall?

Show the answer
A falling object is filmed at a known frame rate beside a metre rule, its position is read off frame by frame, and the acceleration is the gradient of the velocity–time graph.
Terminal velocity and resistive forces

In the falling ball-bearing experiment, how do you know that terminal velocity has been reached?

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The times taken to fall between successive equally spaced marks become equal to one another.
Momentum and impulse

A 0.15 kg ball hits a wall at 8.0 m s⁻¹ and rebounds at 6.0 m s⁻¹. What is the magnitude of its change in momentum?

Show the answer
The velocity changes by 8.0 + 6.0 = 14 m s⁻¹, so the change in momentum is 0.15 × 14 = 2.1 kg m s⁻¹.

The 14 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Scalars, vectors and their representation	Recall questions on scalars and vectors, displacement against distance, representing vectors, velocity and acceleration, accelerating at constant speed, average speed and velocity over a lap, the change in a vector and a rebounding ball, the resultant of two vectors, and free-body force diagrams for a book on a table and a block on a slope.	17
Resolving and adding vectors	Recall questions on splitting a vector into perpendicular components, combining perpendicular vectors for magnitude and direction, scale drawings, and problems on boats, aircraft and a rope at an angle.	15
Describing motion: displacement, velocity and acceleration	Recall questions on average and instantaneous velocity, average speed against average velocity, (u + v)/2 and why it needs constant acceleration, uniform acceleration and its unit, cyclist and train calculations, negative acceleration, zero velocity with non-zero acceleration, choosing a positive direction, and finding instantaneous velocity from readings.	14
Motion graphs	Recall questions on the gradients of displacement–time and velocity–time graphs, the areas under velocity–time and acceleration–time graphs, graphs for constant velocity and uniform acceleration, tangents to curves, irregular areas and areas below the axis, a ball thrown upwards and caught, and a decreasing positive gradient.	15
The kinematic equations for constant acceleration	Recall questions on the equations linking velocity, acceleration, time and displacement, the condition for using them, choosing one when time is unknown, vertical motion under gravity, and sign conventions.	16
Projectiles and motion in two dimensions	Recall questions on the independence of perpendicular motions, the horizontal and vertical motion of a projectile, its parabolic path, a dropped and a rolled ball landing together, time of flight and range for a ball leaving a table or launched at 30°, velocity at the highest point, air resistance, constant vertical acceleration, a boat crossing a current, and perpendicular forces.	15
Measuring motion in the laboratory	Recall questions on light gates, ticker tape and video analysis, needing a known length in shot, air tracks and friction-compensated runways, and why a gate gives an average velocity.	14
Determining the acceleration of free fall	Recall questions on the trapdoor and electromagnet method, working from height and time, what to plot and its gradient, a systematic timing error, light gates, and why mass does not matter.	12
Newton's laws of motion	Recall questions on Newton's first, second and third laws, F = ma from the momentum form, resultant force, car and football calculations, why third law pairs never cancel, the partner of a book's weight, a passenger thrown forwards, the newton, mass as inertia, rocket propulsion, and the floor force in an accelerating lift.	15
Terminal velocity and resistive forces	Recall questions on how acceleration changes during a fall, the velocity–time graph, forces on a ball bearing in a viscous liquid, marker placement, nested paper cones, and falling in a vacuum.	12
Momentum and impulse	Recall questions on defining momentum and impulse, their units, impulse as the area under a force–time graph, why rebounds change momentum most, crumple zones and catching, and average force.	14
Conservation of momentum and collisions	Recall questions on the conservation of momentum and why it follows from Newton's third law, the condition for it, trolleys sticking together and the kinetic energy lost, elastic and inelastic collisions, trolleys pushed apart by a spring, signs for direction, head-on collisions, gun and rifle recoil, air track tests, and the Earth's unnoticed momentum change.	14
Work, energy and its conservation	Recall questions on work done ΔE = FΔs and FΔs cos θ, forces at right angles to motion, the joule, conservation of energy, kinetic energy Eₖ = ½mv² and gravitational potential energy mgh with calculations, the landing speed v = √(2gh), why doubling speed quadruples kinetic energy, braking, and energy lost to friction.	16
Power and modelling motion in small time steps	Recall questions on power and the watt, power = ΔE/t and power = Fv, climber, car and motor calculations, why higher speeds need more power, iterative models of motion and their two update rules, why start-of-interval velocities underestimate displacement, smaller time steps, and modelling forces that vary with speed.	15

Space, Time and Motion is 204 of the 2,455 questions in the guide.Get the guide, £8

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.