How It Works: GPE and KE Exchange
Part of Gravitational Potential Energy — GCSE Physics
This how it works covers How It Works: GPE and KE Exchange within Gravitational Potential Energy for GCSE Physics. Revise Gravitational Potential Energy in Energy for GCSE Physics with 15 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 7 of 16 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 7 of 16
Practice
15 questions
Recall
6 flashcards
⚙️ How It Works: GPE and KE Exchange
When an object falls freely (no friction or air resistance), all its gravitational potential energy converts to kinetic energy. This is the basis for most GPE-to-speed calculations.
The key equation is: GPE lost = KE gained, which means mgh = ½mv². Notice that mass (m) appears on both sides — it cancels out! This means the final speed of a falling object does not depend on its mass (ignoring air resistance). A feather and a cannonball would hit the ground at the same speed in a vacuum.
In reality, air resistance means lighter objects are slowed more relative to their weight. But in GCSE calculations, unless told otherwise, assume all GPE converts to KE.