2.4 Circular motion in a horizontal plane

when an object experiences a net force of constant magnitude perpendicular (at an angle of 90 degrees) to its velocity, it will undergo uniform circular motion, including circular motion on a horizontal plane and around a banked track, and vertical circular motion

What is circular motion?

the ball’s speed is constant
yet, ball’s velocity is constantly changing * not its magnitude, its direction = always tangenital to the ball’s path * AKA the ball will carry on in the direction which it was moving when you let go

Centripetal acceleration

any change in velocity, even if it doesn’t affect an object’s speed = acceleration
objects in circular motion are experincing acceleration towards the centre = centripetal (‘centre-seeking’)

Centripetal force

centripetal acceleration, according to Newton’s 2nd law must be caused by an unbalanced force that constantly pulls the object towards the centre of the circle: a centripetal force * can be provided by a number of different forces: tension, gravity, friction and others

Centrifugal force

if you are rotating (on a ride, or car making sharp turn) you will experience what seems to be an outward force (e.g. pushing you into your harness or the door of the car)
‘centre-fleeing’ force and it is a fictitious force (only seems to exist in your frame of reference)
from the outside, this may be due to inertia (objects ‘want’ to continue in a straight line - direction of tangential velocity) * experience the centripetal force applied to them in the same way that an object in an elevator experiences apparent weight