Final velocity during braking
During a wind-tunnel trolley trace, an object has initial velocity \(21\,\text{m s}^{-1}\) and acceleration \(-2.75\,\text{m s}^{-2}\) for \(4\,\text{s}\). Calculate the final velocity. Use the diagram before entering the requested value. Enter the numerical result and choose the interpretation that matches the physics meaning.
Worked practice: physics data and result
Read the physical quantities first, then calculate the result and state what it means.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.