A tennis ball is thrown vertically upwards. It rises, reaches its highest point, then falls back down. Explain how the velocity and acceleration of the ball change from the moment it leaves the thrower's hand until it reaches its highest point.

Eduqas GCSE Physics — 4.1 Speed, velocity and acceleration · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

The ball’s upward velocity decreases as it rises because the downward acceleration of gravity reduces its speed.
At the highest point the velocity is zero.
The acceleration is constant throughout the motion, always equal to –9.8 m s⁻².
This acceleration acts downwards, the same direction as gravity, during both the rise and the fall.

Examiner tips

  • Use the word ‘decreases’ for velocity change. State that velocity is zero at the top. Mention that acceleration is constant and equals –9.8 m s⁻². Show that the acceleration is downward (gravity).

Common mistakes

  • Confusing velocity with speed. Saying acceleration changes or is zero. Forgetting to specify the direction of acceleration.

Mark scheme (4 marks)

  1. Velocity decreases (as the ball rises)
  2. Velocity is zero at the highest point
  3. The acceleration remains constant throughout / does not change
  4. The acceleration acts downwards (due to gravity) throughout the motion

Key terms in this question

velocity · acceleration

Related

More Speed, velocity and acceleration questions

▶ Try answering this question with AI marking (free) →