If you've ever wondered what the physics behind space travel are, look at this Tsiolkovsky rocket equation.
We can measure acceleration experienced by an object directly with an accelerometer.
You can derive them from the equations we listed above.
All you need to know is that speed is expressed in feet per second (imperial/US system) or in meters per second (SI system) and time in seconds.
You can find there: Acceleration always occurs whenever there is a non-zero net force acting on an object.
You can feel it in an elevator when you become a little heavier (accelerating) or lighter (decelerating), or when you're riding down a steep slope on your sled in the snow.
Acceleration is the rate of change of an objects speed; in other words, it's how fast velocity changes.
According to Newton's second law, acceleration is directly proportional to the summation of all forces that act on an object and inversely proportional to its mass.
For example, you can find what the momentum change is over a certain time with this formula for momentum.
This is on of the physical quantities we use in our car crash calculator where we explain and visualize the importance of seat belts using numbers, and determine at what speed can you die in a car crash. In it, he formulated the law of universal gravitation which states that any two objects with mass will attract each other with a force exponentially dependent on distance between these objects (specifically, it is inversely proportional to the distance squared).