Gravity

[Yinzer]

What is the force of gravity? Can it even be measured? Becuse there is this acinine commercial for a new vacuum cleaner that creates 100,000 times the force of gravity and I find that hard to beleive. All commercials aside though, I was just wondering about gravity itself.

[stoo_pid]

Without getting too technical, the force of gravity is not constant as it is dependent on the amount of mass a body has. For example, the gravity on Earth is greater than the gravity on the Moon, simply because the Earth has much more matter or mass than the Moon.

Gravity can & has been measured but it's not a very powerful force.  The only reason gravity seems so powerful on Earth is that the planet weighs something like 6 billion trillion tonnes.  Look at it this way, any of us can easily overcome the gravitational force of an entire planet just by picking up a mug of tea.

[New Forester]

The force in the commercial is not gravity, but "centrifugal" force -- more correctly, momentum.  However, if you were a beetle whizzing around inside the vacuum it would seem very similar.

 

If you change the speed or direction of any moving object, it "resists" and you must apply a force.  This is why we are thrown forwards or backwards in a vehicle when it brakes or accelerates, or to the side when it goes round a corner.

 

If you spin something, each bit of it is constantly "trying" to keep going in a straight line, and so must be pulled back to the curve of its rotation.  The faster it goes and the sharper the curve, the more force is needed.

 

The advert you saw was basically saying that the vacuum is spinning stuff very fast indeed (presumably air and dust).  I'm not sure whether the 100,000 figure is a realistic one (it does seem large), as I can't remember the equations to calculate it.

[Yinzer]

Oh, OK I get it. Yes, there indeed used to be an amusement park ride like that. Ir would spin really fast and the floor would drop yet somehow everyone stayed glued to the wall. Thanks folks!

[Peter Pedant]

its F = mv2/r, New forester