Unit 2 · Kinematics and Dynamics

What Cambridge International AS & A Level Physics (9702) Unit 2 covers

Use this map to connect each assessed skill to the relationship or representation that makes it visible.

Kinematics and Dynamics

Connect the published share to the unit model

Take the cart’s initial motion as positive before combining 1.20 m/s with an acceleration of 0.80 m/s². That convention gives meaning to both the calculated 4.80 m/s velocity and the 13.5 m displacement.

The velocity equation supplies an ordinate on a velocity–time graph, whereas displacement comes from ut + ½at² or the area under that graph. Confusing an ordinate with an area changes the requested quantity.

A complete solution retains seconds through each product and ends with forward directions. The sign convention therefore remains visible from setup to interpretation.

For any motion problem, define the positive direction before selecting a graph operation or dynamical law. A graph ordinate, a gradient and an area represent different quantities, so name the operation before using a number. Construct the relation symbolically, substitute consistent SI values, and interpret the sign in words so that velocity, displacement, momentum and resultant force remain directionally consistent.

The decision that organizes this unit

Define the system and choose the route before calculating

Use v = u + at with the chosen positive direction

Mechanism route and repair branches

Relationships to preserve

• Velocity change: Acceleration acts for 4.50 s.
• Displacement: A velocity–time area has unit meters.
• Direction: Velocity and displacement are vectors.

Representations to read

• A graph of velocity (m/s) against time (s).
• A formula card that explains the pair of constant-acceleration equations separates final velocity from displacement.
• A table linking key concept, why it matters, visible method.

Branches to reject

• Using the final velocity as though it were constant for the whole interval
• Using s = ut + ½at² for a velocity coordinate
• Dropping the time unit

How Cambridge International AS & A Level Physics (9702) assesses Kinematics and Dynamics

What a complete response must make visible

Match the task to evidence that a reader can audit, then check the most likely reasoning failure before finalizing the response.

Worked example: motion graphs, momentum and resultant force

Read each question as it appears on the exam paper, choose your answer, then tap it to see the feedback.

Practice 1: Uniformly accelerated motion

Practice 2: Impulse and momentum

Key terms for Unit 2: Kinematics and Dynamics

Models, uses, and boundaries

Kinematics and Dynamics

The pair of constant-acceleration equations separates final velocity from displacement. Use this relationship when the pair of constant-acceleration equations separates final velocity from displacement..

Worked example: motion graphs, momentum and resultant force

Seconds cancel one power from acceleration in v and both powers in the displacement term. Use this relationship when seconds cancel one power from acceleration in v and both powers in the displacement term..

Kinematics and Dynamics: change one condition

Reading the line at 2.50 s and 3.75 s compares velocities, not traveled distances. Use this relationship when reading the line at 2.50 s and 3.75 s compares velocities, not traveled distances..

Kinematics and Dynamics: test proposed results

Candidate values should respect the positive direction and constant 0.80 m/s² gradient. Use this relationship when candidate values should respect the positive direction and constant 0.80 m/s² gradient..

Cambridge International AS & A Level Physics (9702) Unit 2 FAQ

Evidence workshop

Continue from the free model into complete practice

The full unit guide continues with the chapter’s worked examples, figures, scoring tables, and answer checks.

• Worked example: motion graphs, momentum and resultant force
• Kinematics and Dynamics: change one condition
• Kinematics and Dynamics: test proposed results
• Check the worked-example evidence for Kinematics and Dynamics

Related Cambridge International AS & A Level Physics (9702) unit guides

How to study Cambridge International AS & A Level Physics (9702) Unit 2

Start with the organizing decision

Before solving, restate the decision in operational terms: Show how (m/s²) × s becomes m/s in the velocity line and how the extra factor of time produces meters in the displacement line.. Your first written move should be to Use v = u + at with the chosen positive direction.

Practice the same idea in several representations

Rotate through A graph of velocity (m/s) against time (s)., A formula card that explains the pair of constant-acceleration equations separates final velocity from displacement., A table linking key concept, why it matters, visible method.. Use each representation to practice Motion Graphs and the Equations of Uniformly Accelerated Motion, Free Fall and Projectile Motion, Newton's Laws of Motion, Mass, Weight and Momentum, Non-uniform Motion: Friction, Drag and Terminal Velocity, Conservation of Linear Momentum: Elastic and Inelastic Collisions, and explain what stays invariant when the surface form changes.

Turn each error into a repair check

After every attempt, audit the response for Using the final velocity as though it were constant for the whole interval; Using s = ut + ½at² for a velocity coordinate; Dropping the time unit. Then redo only the first step that made the reasoning diverge, keeping units, direction, and model conditions visible.

Confirm current course details in the official Cambridge International syllabus for the 2025-2027 administration.

Where to go next

Return to the Cambridge International AS & A Level Physics (9702) to see every unit and plan your revision.