PHYSICS CONNECTION
Changing drag produces changing acceleration
As a falling object speeds up, drag usually increases. The resultant force becomes smaller, so its acceleration falls until terminal velocity is reached.
Downward resultant = weight − drag − upthrust
Follow the reasoning
- Draw all forces, including upthrust when significant.
- Find the resultant at the speed being considered.
- Use Newton’s second law to infer the acceleration.
OFFICIAL OCR QUESTIONS
Try it in a past paper 2
Open the question, then use its mark scheme to check your work.
Question 24(a)
Explain terminal velocity using the resultant force.
Question 1(d)–(e)
Use tangents and terminal speed to analyse a steel ball falling through oil.
A curated collection checked against the question papers and mark schemes; not a complete past-paper catalogue. Links open official OCR PDFs in a new tab.
ORIGINAL PHYSICSUK QUESTIONS
Put the ideas to work
More practice is on its way
No PhysicsUK question linked yet. New eligible questions appear here as the bank grows.
Specification outcomes (6)
- 3.2.2(a) Define drag as the frictional force experienced by an object travelling through a fluid.
- 3.2.2(c) Describe motion of objects falling in a uniform gravitational field in the presence of drag.
- 3.2.2(d)(i) Define and describe terminal velocity.
- 3.2.1(a) Apply Newton’s second law, F = ma.
- 3.2.1(c) Understand weight of an object, W = mg.
- 3.2.1(e) Draw and interpret free-body diagrams.