Start with kinematics language if distance and displacement, or speed and velocity, are still easy to confuse.
Kinematics practice questions with answers
These three original MathLab examples move from a direct calculation to interpreting a reversal. Attempt them before opening the worked solutions.
Foundation: read a velocity graph
A straight-line velocity–time graph runs from to , with time in seconds and velocity in metres per second. Find the acceleration and displacement over these four seconds.
Answer and check your working in the MathLab app.
Your next step is in MathLab.
Download MathLab for iPhone to enter answers, get feedback and keep practising with hints and worked solutions.
Get MathLabWorked answer: gradient and trapezium area
Acceleration is the gradient: . Displacement is the area: . Velocity stays positive, so distance is also m.
Standard: choose a SUVAT equation
A cyclist moving at accelerates uniformly at over a displacement of m. Find the final speed.
Answer and check your working in the MathLab app.
Your next step is in MathLab.
Download MathLab for iPhone to enter answers, get feedback and keep practising with hints and worked solutions.
Get MathLabWorked answer: use the equation without time
Use : . The cyclist continues in the positive direction, so . The final speed is to three significant figures.
Reasoning: distance is not displacement
A particle has velocity for , in SI units. A student says it travels no distance because its final displacement is zero. Explain the error and find the distance.
Answer and check your working in the MathLab app.
Your next step is in MathLab.
Download MathLab for iPhone to enter answers, get feedback and keep practising with hints and worked solutions.
Get MathLabWorked answer: split at the change of direction
Velocity changes sign at . The positive area is m; the negative area is m. They cancel for displacement, but distance adds their magnitudes: m. The particle returns to its starting position after travelling away from it.