On 10/08/15 01:56, Tudor Hughes wrote:
On Sunday, 9 August 2015 16:47:13 UTC+1, RedAcer wrote:
On 08/08/15 12:26, Alastair wrote:
I learnt my Kinematics at University while studying for an
engineering degree, not from some smart alec teacher. Yours
wasn't Dawlish by an chance? OK the centrifugal force is not a
force field like gravity, magnetism, etc., but the centrifugal
force can be calculated, see your link which describe it
http://scienceworld.wolfram.com/phys...ugalForce.html .
That link is proof enough for me. Strange that one can get so
many hits for centrifugal force if it does not exist.

Nonsense. If you were in a seat on a roundabout facing inwards then
you would feel a force pressing into you back forcing you to move
in a circle. Try this experiment. Take a short piece of sting with
a weight on the end and whirl it round in a vertical circle. As the
weight is at the top of the circle, let go. If there was a
centrifugal force it should move outwards. It doesnt though. It
will move off horizontally at a tangent to the circle.

Hmm, some doubtful stuff there. From the point of view of the
rotating body centrifugal force certainly exists and is a useful if
non-rigorous concept. When you let go of the string the body the
body certainly does initially accelerate outwards at a rate
determined by the previous centrifugal force.

No that is not correct. When you let go/cut the sting the tension
towards the centre forcing the ball to move in a circle stops. At that
instant the velocity of the ball is horizontal. According to Newtons
laws it will continue to have a horizontal velocity.