Question

Where do we experience centripetal force around us in real life. When would we use this concept "centripetal force" and "centripetal acceleration." I am trying to understand this concept and break it down in real life and in physics problem.

Answer 1

We experience centripetal force everyday in our life like taking a turn in a car, turning around a corner, swinging a stone tied to a string etc...The concept of centripetal force is quite simple. Consider a body going around a circular path, at every instant we can see that the direction of motion of the body is changing. The direction of motion is always tangential to the circular path at a point. Since the direction is changing at every instant, the velocity is not constant, it is variable. This change in velocity results in an accleration. This acceleration is called 'Centripetal acceleration'. It is always directed towards the centre of the circular path. It is given by,

where v is the velocity and r is the radius of circular path.   

We know if there is an accleration, a force must be producing it. The force which produces centripetal acceleration is called 'Centripetal force'. It is always directed towards the centre of circular path. This force keeps the body in circular path otherwise the body will travel tangentially in the direction of velocity at any instant. The centripetal force is given by,

  

For example, when we are swinging a stone tied to the end of the rope in a circular path. Whenever we leave the string the stone moves tangentially in the direction of velocity. So, every point the stone is trying to move in the direction of velocity but the centripetal force keeps it in the circular path. Here, the centripetal force is provided by the tension in the string. Similarly, the gravitational force between the Earth and Sun acts as the centripetal force.