Do helicopters justify the noise they make?
We know that noise is evidence of inefficiency, so that to a deranged mind it might seem that such justification is no less important than that of cars and aeroplanes.
In comparison we refer briefly to powertools, which besides that of cutting costs, provide their justification by allowing us to achieve more in our leisure hours.
We must exclude military helicopters as we do not like war. We do not like war, as it justifies all measures.
We therefore start with mountain rescues: a noble goal. But one which does not concern those of us who are happy to stay in the city. Mountain rescue helicopters get the green light.
Then, within a city, certain patients may have little chance if the ambulance gets stuck in traffic which the city doesn't know how to manage. With the proviso that ambulance companies deal out immediate death to any crew which uses their emergency lights to get to a fast food outlet, rescue helicopters all get the green light.
Following this is vehicle recovery: but we are not privy to the success rate. We have no choice but to leave tracking companies to their own devices.
But what of the science of them? Don't helicopters inspire children with an interest in science itself?
Consider a circle to which we ascribe mass; as yet it has no cross-sectional area. We choose an arbitrary point on it and call it a. We place this circle with the origin at the centre and allow it to rotate. The angle it has rotated by, we call b. Our velocity is described as ie^i(b+a). Now we give our circle an infinitesimal cross-sectional area: the point a, the infinitesimal mass c. We must consider the change in mass*velocity. This is given by -ce^i(b+a), is called the centripetal force, and is produced by the mere fact of the circle being a solid.
Let us observe a particle that becomes detached from the spinning circle. Becoming detached at 0°, once the circle has turned 90°, the particle will have reached 1+(π/2)i (on a unit circle). Simply put, centrifugal force is the tendency for things to travel in a straight line.
We will then label a few more points and look at the circle from the side.
But this is about as far as I feel I need to go: do we need anything other than the written word, to interest us in learning?