Physics

Understanding Acceleration: The Rate of Change in Motion

Published on June 19, 2025 by Unitly Team

Acceleration describes how velocity changes over time. This guide covers what it means, how it's measured, and real‑world uses.

What is Acceleration?

Rate of change of velocity with respect to time; a vector with magnitude and direction. Speeding up, slowing down, or turning are all acceleration.

Key Formula

a = Δv / Δt

Measuring Acceleration

Units (SI and others):

  • m/s² — SI
  • cm/s² — 0.01 m/s²
  • ft/s² — 0.3048 m/s²
  • in/s² — 0.0254 m/s²
  • g — 9.80665 m/s²

Types of Acceleration

Linear Acceleration

Change in speed along a straight line:

  • Car 0→60 mph
  • Elevator start
  • Roller coaster drop

Angular Acceleration

Change in rotational speed:

  • Spinning top slowing
  • Ceiling fan starting
  • Wheel during braking

Real‑World Examples

Everyday Life

  • Car: ~2–3 m/s²
  • Elevator: ~1–2 m/s²
  • Free‑fall g: 9.81 m/s²

Extreme

  • F1 braking: up to ~6.5 m/s²
  • Shuttle launch: ~3g
  • Bug on windshield: ~100,000 m/s²

How is Acceleration Measured?

  1. Accelerometers
  2. IMUs (aerospace/robotics)
  3. High‑speed cameras
  4. Radar guns

Did You Know?

Rimac Nevera: 0–60 mph in 1.85 s (~1.5g).

Applications of Acceleration

Transportation

  • Airbags/ABS
  • Ride comfort
  • Takeoff/landing

Technology

  • Phone orientation
  • Game controllers
  • Wearables

Practical Tip

Support head/neck during rapid acceleration or deceleration to avoid injury.