Acceleration is the rate of change of the velocity of a moving body. It is a fundamental concept in physics and is usually expressed in units such as feet per second per second (ft/s²) or meters per second per second (m/s²). Acceleration can be understood as how quickly the velocity of an object changes over time.
Key points about acceleration:
- Vector Quantity: Velocity is a vector quantity, meaning it has both magnitude and direction. Therefore, a body moving at a constant speed can still be accelerating if its direction changes.
- Newton’s Second Law: According to Newton’s second law of motion, a body will experience acceleration only if there is an unbalanced or resultant force acting on it.
- Acceleration Due to Gravity: Acceleration due to gravity represents the acceleration of a freely falling body under the influence of Earth’s gravitational field. This acceleration is approximately 32.174 ft/s² or 9.806 m/s², and it varies slightly with latitude and altitude.
- Formula for Average Acceleration: The average acceleration (a) of an object moving in a straight line over a time period (t) can be calculated using the formula:
or, if initial velocity () and final velocity () are known:
A negative value indicates deceleration or slowing down.
Understanding acceleration is crucial in analyzing the motion of objects, whether they are speeding up, slowing down, or changing direction. It plays a fundamental role in classical mechanics and is a key concept in fields such as physics and engineering.