Acceleration: GCSE Physics Definition

Katie M

Written by: Katie M

Reviewed by: Ann Howell

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2 minutes

What is acceleration?

In GCSE physics, acceleration is the rate of change of velocity. It is measured in metres per second squared (m/s2).

Acceleration is a measure of how much an object's velocity changes every second. It can be calculated using the equation:

acceleration space equals space fraction numerator change space in space velocity over denominator time end fraction

The change in velocity is equal to the difference between the initial and final velocity, so the equation can also be written as:

acceleration space equals space fraction numerator final space velocity space minus space initial space velocity over denominator time end fraction

Like velocity, acceleration is a vector quantity. This means it has both a magnitude and a direction. This is important because it means acceleration can have a positive or negative value

  • Acceleration is positive when an object speeds up e.g. a rocket accelerating upwards

  • Acceleration is negative when an object slows down e.g. a car decelerating when the brakes are applied

  • Acceleration can be positive or negative when an object moves with constant speed but changes direction e.g. an object moving in a circle

Illustration showing a car decelerating at -5 m/s² with a person gesturing to the car to stop, and a rocket accelerating upwards at +30 m/s².
If a car travelling at 20 m/s decelerates at a rate of -5 m/s², they will come to a stop in 4 seconds. In the same amount of time, a rocket accelerating upwards at +30 m/s² would reach a speed of 120 m/s.

Acceleration revision resources to ace your exams

You can speed up your understanding of acceleration by checking out our GCSE physics resources, including expert-written revision notes and exam questions. These are tailored to your specific exam board, whether you are taking AQA, Edexcel, OCR or WJEC.

Explore Our GCSE Physics Revision Resources

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Katie M

Author: Katie M

Expertise: Physics

Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.

Ann Howell

Author: Ann Howell

Expertise: Physics Content Creator

Ann obtained her Maths and Physics degree from the University of Bath before completing her PGCE in Science and Maths teaching. She spent ten years teaching Maths and Physics to wonderful students from all around the world whilst living in China, Ethiopia and Nepal. Now based in beautiful Devon she is thrilled to be creating awesome Physics resources to make Physics more accessible and understandable for all students, no matter their schooling or background.

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