Reply to: What's the fastest recorded speed you've achieved without the use of an engine?

[realityhack]

About 90mph, during a ~300ft bungee jump.
55mph on the bike.
About 30mph on inline skates down a very steep hill - a VERY stupid thing to do.

[gingerjedi]

I never did get this? Yould think the fastest you could go would be as fast as the wind - else the sail will act as a big airbrake. That's why I gave up maths post A Level. I guess you aren't sailing with the wind directly behind - maybe across it, and then just using the force of the wind on the sail in some variation of f=ma. i.e a=f/m. As the speed increases the force drops and therefore acceleration becomes zero.

Yep, you travel faster sailing at around 90 degrees to true wind and as you speed up you have to take 'apparent' wind into account and streamline the sail. It helps to think of it as a foil rather than a sail.



Travelling faster than the wind is a lot easier on wheels (ice is even faster) as you don't have to contend with the resistance created by water.

You can't travel downwind faster though... unless you're this guy:

[IR35FanClub]

Around 45mph in a small production class land yacht, the record for mini yachts is 64.4mph.

You can travel at double the wind speed up to about 35mph but above that the ratio decreases the faster you go.

I never did get this? Yould think the fastest you could go would be as fast as the wind - else the sail will act as a big airbrake. That's why I gave up maths post A Level. I guess you aren't sailing with the wind directly behind - maybe across it, and then just using the force of the wind on the sail in some variation of f=ma. i.e a=f/m. As the speed increases the force drops and therefore acceleration becomes zero.

[NotAllThere]

Felix - Mach 1.2

[rhubarb]

I should imagine that any practitioner of free fall skydiving would regularly achieve the terminal velocity of 125mph.

Not that I've ever done it mind you. Gives me sweaty palms just watching those chaps.

Yep, would have achieved this during my VERY brief stint of learning to skydive.
Lesson 1. Slight hesitation in the doorway as I considered NOT jumping out the plane.
Did jump.
All went really well until I neared the ground. I ended up floating about 20 feet above the same plane I'd jumped out of a few minutes earlier as it taxied along the ground. Scared the life out of me.
So that was that.
Stupid "sport".

[Robinho]

60 knots, glide landing in a Cessna 152.

[gingerjedi]

Around 45mph in a small production class land yacht, the record for mini yachts is 64.4mph.

You can travel at double the wind speed up to about 35mph but above that the ratio decreases the faster you go.

[Malcolm Buggeridge]

I should imagine that any practitioner of free fall skydiving would regularly achieve the terminal velocity of 125mph.

Not that I've ever done it mind you. Gives me sweaty palms just watching those chaps.

[Mich the Tester]

About 45mph, last week at the Apeldoorn velodrome, dropping off the banking onto the straight. Didn't keep up that speed for long though.

[MarillionFan]

35mph downhill from Salisbury Plain to the White Horse on a mountain bike with thick offroad tyres.

[Old Hack]

56 mph downhill on the A38 on a PlanetX carbon bike, and about 55-60mph flying through the air on the way to breaking both legs in Gressoney la Trinite whilst attempting to show people how good I was at going fast on snow. 1991.

[kingcook]

17mph, raising to 21mph briefly at the vinegar stroke.

[NotAllThere]

60mph - but in control, on my skis.

[EternalOptimist]

about 60 mph.

I came down the tiger slope at glenshee on me bum, having lost my skis at the top due to a newbie error.
a man on his bum, lubricated by a thin coating poo, can outstrip an olympic speed skier, and I proved it.

luckily there was a sturdy fence at the bottom else I would be well on my way to Antarctica by now

[SimonMac]

About 28mph

What's the Average Speed of Male Ejaculation?