Retrieval Practice
Motion Along a Straight Line — AQA A-Level Physics
Q1. Define displacement.
The distance of an object from a fixed point in a specified direction.
Q2. What does the gradient of a displacement-time graph represent?
Velocity.
Q3. What does the area under a velocity-time graph represent?
Displacement.
Q4. What does the area under an acceleration-time graph represent?
Change in velocity.
Q5. State the four SUVAT equations.
v = u + at, s = ut + 0.5at^2, s = (v+u)t/2, \(v^{2}\) = \(u^{2}\) + 2as.
Q6. When can SUVAT equations be used?
Only when acceleration is constant (uniform acceleration).
Q7. What is terminal velocity?
The constant maximum velocity reached when drag equals weight, giving zero resultant force and zero acceleration.
Q8. In the free-fall practical, what graph do you plot and what does the gradient give?
- Plot 2h/t against t.
- The gradient gives g (acceleration due to gravity).
Q9. How do you find instantaneous velocity on a curved displacement-time graph?
Draw a tangent at the required time and calculate its gradient.
Q10. Why does a heavier skydiver have a higher terminal velocity?
- Their greater weight requires a larger drag force to balance it.
- A larger drag only occurs at a higher speed.
Q11. What key phrase tells you u = 0 in a SUVAT problem?
'Starts from rest' means the initial velocity u = 0.
Q12. Name one systematic and one random error in the free-fall g experiment.
- Systematic: residual magnetism delays release, increasing t.
- Random: parallax error reading the ruler.