Science
What is Acceleration?
Acceleration is how quickly an object's velocity changes — speeding up, slowing down, or changing direction. When you press a car's accelerator, you increase its velocity; braking is acceleration in the opposite direction (deceleration).
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains acceleration.
Key things to understand
- 1Acceleration = change in velocity ÷ time taken. Its units are metres per second squared (m/s²).
- 2It happens whenever velocity changes — getting faster, slower, or turning.
- 3A force is what causes acceleration: Newton's second law says force = mass × acceleration (F = ma).
- 4Near Earth's surface, gravity accelerates falling objects at about 9.8 m/s².
Frequently asked questions
- Is slowing down acceleration?
- Yes. Any change in velocity is acceleration. Slowing down is acceleration in the direction opposite to motion, often called deceleration.
- What causes acceleration?
- A net force. By Newton's second law, the bigger the force (or the smaller the mass), the greater the acceleration: F = ma.
- Can something moving at constant speed be accelerating?
- Yes — if it's changing direction, like a car going around a bend or a planet orbiting the Sun, its velocity is changing, so it's accelerating.