Acceleration

All of us today are familiar with the term acceleration. The driver of a car pushes their foot down on the accelerator petal and the car goes faster or increases in speed.

Scientists use the word ‘acceleration’ for any change in the velocity of an object. The velocity of an object is distance an object travels in a straight line per unit of time. So if there is a change in the magnitude or in the direction of an object, scientists say that there is a change in the acceleration.

A satellite orbiting the Earth and a constant speed is continually changing direction. This means that it is continually accelerating.

Well, what causes an object to accelerate? Sir Isaac Newton, a famous English scientist stated in his first law of motion ‘that a body will remain at rest or in constant motion unless it is acted upon by a force’

Sir Isaac Newton

An object at rest will stay at rest because it has zero force acting upon it. A body in motion will also continue in motion unless acted upon by a force. Without the force of your seat belts holding you back in your seats your body would continue to move forwards and sometimes with fatal results if your car came to a sudden screeching holt.