anonymous one year ago Any object moving in a circle has a force acting on it towards the centre of the circle. What does this force do to the object?

1. Michele_Laino

that force bends the trajectory of the object, so the trajectory of such object results in a circumference, in other words the circular trajectory is the effect of the action of such force, and such force is called centripetal force.

2. greatlife44

My physics knowledge which is beginning to allude me but when you move in a circle, say at a certain speed, there is a velocity? why? because by moving in a circle, the direction is always changing so there's a velocity to accompany that. furthermore, we can see that there will always be an acceleration vector that's not only faces towards the center of the circle at all times, but also is perpendicular to your velocity vector. perpendicular means, the two vectors make an angle of 90 degrees. |dw:1441741357541:dw| centripetal acceleration is defined as this. $a_{c} = \frac{ v ^{2} }{ r }$ what if we keep all other variables constant and say increase r the radius. well, your acceleration Ac would be. Play around with the formula and say "oh if I keep these variables constant" while adjusting the other then what happens now? @michele_laino I have heard that the centripetal force is not actually a force, what are your thoughts about this?

3. Michele_Laino

let consider a car which travel in a circular track, then in order to bend the trajectory of the car, the driver have to exert a force by means of the steering wheel of his car, well that force is the $$\large centripetal\; force$$. Now, that car is not an inertial system, since an acceleration is acting inside it, in fact the driver feels a continuous boost in the same direction and opposite orientation with respect to the centripetal force. Since that boost is not coming from a contact with any other body and the driver, we say that a fictitious force is acting on the driver and on any other person and object inside that car as well, we name that fictitious force $$\large centrifugal\; force$$ |dw:1441742946838:dw|

4. greatlife44

I must understand this! When, say a person undergoes a sharp turn the force that pulls him inward, is an actual force that's the centripetal force. It is hard form to visualize this boost, can I just say that this concept is a non entity, something that does not exist? if this force is fictitious, then does it have any bearing on calculations? |dw:1441744245765:dw|

5. greatlife44

@Michele_Laino

6. Michele_Laino

not exactly the centrifugal force, is the fictitious force, and it pulls every person and object inside the car outward. When you go by car, and you are going to travel a curve, you feel a force which pulls you at the opposite side with respect to the center of curvature of the trajectory of your car, well that force is the centrifugal force |dw:1441745690785:dw| @greatlife44

7. greatlife44

I see, novice physics person here. if the car is moving in a circle, it seems that the centrifugal force is opposite the centripetal acceleration, Why doesn't an object fall towards the center? does this centrifugal force help to counteract this phenomena given that it's in opposite direction from the centripetal acceleration? furthermore how do we calculate the centrifugal force? I had a physics teacher who said that the term 'centrifugal' is not really a term and should be disregarded. |dw:1441757493626:dw| @Michele_Laino @rvc

8. rvc

centrifugal force has the magnitude same as that of the centripetal force. the direction of both the forces is opposite. the centripetal force acts towards the centre while the centrifugal force acts away from the centre. the centrifugal force helps to keep the body in motion.