The Forces on a Falling Object — Step by Step
Part of Terminal Velocity — GCSE Physics
This deep dive covers The Forces on a Falling Object — Step by Step within Terminal Velocity for GCSE Physics. Revise Terminal Velocity in Extra Topics for GCSE Physics with 13 exam-style questions and 11 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 2 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 13
Practice
13 questions
Recall
11 flashcards
💪 The Forces on a Falling Object — Step by Step
Figure 1: How the balance of forces changes as a skydiver accelerates towards terminal velocity
Understanding terminal velocity is really about tracking two forces and how they change relative to each other as speed increases.
Stage 1 — Just After Starting to Fall
Weight (downward) is much greater than drag (upward). The resultant force is large and downward, so the object accelerates rapidly at close to 10 m/s² (gravitational field strength, g).
Stage 2 — Speeding Up
As speed increases, drag increases too. This is because drag depends on speed — roughly proportional to speed squared for most objects. The resultant force is still downward, so the object still accelerates, but the acceleration is now smaller than before.
Stage 3 — At Terminal Velocity
Eventually drag equals weight. The resultant force is now zero. By Newton's Second Law (F = ma), if F = 0 then a = 0. The object moves at a constant velocity — this is terminal velocity.
It is important to note that the object is still moving and still falling — it just isn't speeding up any more.