On 23/08/2019 13:17, Robin wrote:
On 23/08/2019 11:17, The Natural Philosopher wrote:
On 23/08/2019 10:34, Mike Clarke wrote:
On 23/08/2019 08:14, The Natural Philosopher wrote:

All force, no distance
An infintely large infinitely strongÂ* helicopter could hover with no
power input.

Not so. It's having to generate lift with the rotating rotor blades.
The work is proportional to the torque on the rotor shaft and the
number of revolutions.

An infintely large rotor turns at zero RPM

There are no revolutions.



if it is also an infinitely heavy helicopter I'd like to see the proof

if it isn't infinitely heavy why bother with rotors when you could just
use cavorite?


The point is that it takes no energy to hover since no potential energy
is lost or gained.

It takes energy to accelerate an air mass downwards to generate the
momentum change that provides the lift.

But energy is 1/2mV^2 whereas momentum is mV so as m tends to infinity V
tends to zero for the same lift

That is, an infinitely large rotor.

If you google the man powered helicopter you will see it has a rotor the
size of a tennis court


--
How fortunate for governments that the people they administer don't think.

Adolf Hitler