Everyday Speeds and Accelerations

Speed is measured in metres per second (m/s) or kilometres per hour (km/h).
Speed is a measure of distance travelled in a certain amount of time.
An object’s speed can change - it may speed up, slow down, or change direction.
An average speed is calculated by dividing the total distance travelled by the total time taken.
Speeds of everyday things can vary drastically: walking (~1.5 m/s), running (~3 m/s), cycling (~6 m/s), driving a car (~15 m/s), or the speed of a commercial jet (~250 m/s).
It is important to understand and estimate everyday speeds, to solve practical problems or answer questions about distance, time, and speed.

Acceleration is a measure of how quickly an object changes its speed.
It is measured in metres per second squared (m/s²).
Positive acceleration (or simply accelerating) means an object is speeding up, while decelerating (or negative acceleration) means it’s slowing down.
Even if an object changes its direction but keeps a steady speed, it is still accelerating, because its velocity (speed and direction) is changing.
Acceleration due to gravity is an important constant, approximately 9.8 m/s². This is the rate at which objects fall towards Earth if there is no air resistance.
Real-life examples of acceleration include: a car going from 0 to 60 mph in a matter of seconds, a plane during takeoff, or an object being dropped from a height.
Acceleration calculations can be made using the formula: Acceleration = Change in Speed / Time Taken.
It’s crucial to understand acceleration as it is involved in many areas of physics, especially when studying forces and motion.