IB Physics HL A.1.5 Instantaneous and average values in changing motion Question Bank

Practise IB Physics HL A.1.5 by analysing instantaneous values and vector averages across changing, multi-stage motion.

Exam points

Use gradients and signed displacement data to compare instantaneous and average velocity.
Analyse a multi-stage path and distinguish scalar average speed from vector average velocity.
Evaluate an estimate of an instantaneous value by considering tangent choice, scale and uncertainty.

[Maximum number: 3]

A ball is released near the surface of the Moon at time t=0. The point of release is on a straight line between the centre of Earth and the centre of the Moon. The graph below shows the variation with time t of the displacement s of the ball from the point of release.

Figure for Question A.1.5—Instantaneous and average values question 1 — IB Physics HL

Use the graph to

estimate the velocity of the ball at $t=0.80 \mathrm{~s}$ .

tangent drawn to curve at 0.80 s ;
correct calculation of gradient of tangent drawn;
$-1.3 \pm 0.1 \mathrm{~m} \mathrm{~s}^{-1}$ or $1.3 \pm 0.1 \mathrm{~m} \mathrm{~s}^{-1}$ downwards;
or
correct coordinates used from the graph; substitution into a correct equation;
$-1.3 \pm 0.1 \mathrm{~m} \mathrm{~s}^{-1}$ or $1.3 \pm 0.1 \mathrm{~m} \mathrm{~s}^{-1}$ downwards;

All question bank results loaded

A.1.5—Instantaneous and average values question 1