1/4 Mile Sprints

[sAsLEX]

. The less distance from the centre, the greater the force. This is perhaps the trickiest relationship, for it is much harder to stay near the middle of the merry-go-round than the edge of the merry-go-round.

ahem, pulls trusty 7th form physics book again from the depths of darkness


Fc=(m*v^2)/r ie mass times velocity squared over the radius gives centripetal force

Velocity is a linear measure therefore v=r*w(funny greek w)
w(funny greek w)=2*PI*f(frequency) 360RPM=6Hz

so back to origanal equation after playing with some letters

Fc=m*r*w^2.here radius a multiplier the force increases the further you get out for a set rotational speed such as in a merry go around

[Jamezo]

I'm sure all riders who have highsided would be fascinated to learn that centrifugal force is a myth...

However your are right in your assertion. Centrifugal force does not exist. Nevertheless, it appears real to the object being rotated. This is because the object believes that it is in a non-accelerating situation, when it is not. For instance, a child on a merry-go-round is not experiencing any real force outward, but they must exert a force inwards to keep from flying off the merry-go-round. Since the centrifugal force appears so real, it is often very useful to use as if it were real. The more massive the object, the greater the force. This is true because an adult will have a harder time staying on a merry-go-round than will a child. The greater the speed of the object, the greater the force. This is true because a merry-go-round is harder to stay on, the faster it is pushed. The less distance from the centre, the greater the force. This is perhaps the trickiest relationship, for it is much harder to stay near the middle of the merry-go-round than the edge of the merry-go-round.

hmm, the acceleration of the adult and child will be equal, I don't see why an adult will have a harder time staying on, unless you are implying that this adult does not have strength proportional to their mass, relative to the child.

if you have personally experienced this, this effect might be explained by your higher center of gravity, that's the only reason I can surmise for an adult having any worse ability to stay on a merry-go-round.

[Jamezo]

ahem, pulls trusty 7th form physics book again from the depths of darkness


Fc=(m*v^2)/r ie mass times velocity squared over the radius gives centripetal force

Velocity is a linear measure therefore v=r*w(funny greek w)
w(funny greek w)=2*PI*f(frequency) 360RPM=6Hz

so back to origanal equation after playing with some letters

Fc=m*r*w^2.here radius a multiplier the force increases the further you get out for a set rotational speed such as in a merry go around

your own equation belies you, you stated before, v=r*w, therefore w=v/r

increasing the radius decreases the value of w, and since in your next equation, Fc=m*r*w^2, the w is raised to the power of 2, it has more effect on the force than the radius alone. increasing the radius decreases the force.

yousa needa ride some more roundbouts!

[mangell6]

I remember this being taught and I thought then as I do now, I'll never use this in real life.

Mike

BTW It was me who stopped the Harley Rider.

[matthewt]

I'm still accelerating while going through the 1/4 mile, even at the end, which is a pity as it could go faster.

If you guys were still accelerating on the run then you should of started further back. When TonyS broke 5 seconds that's exactly what he did. He started back by the barrage gates and was probably doing 160 by the time he went past the starting point.

Anyway well done to all.

My effort was 222k (best of 2 runs) on the flying and 11.43 (only 1 run) on the standing. Last year my F4 did 248k and 11.30 so I'm happy with the results.

[matthewt]

I suppose given all of the nice things I have to say about Motomart I had better make other plans...

Do you need me to hold your hand

Seriously, though you should come along anyway. Besides Sparky Bills is probably the only one on this site and we could both take him :sly:

[mangell6]

I did notice that I was going faster just before the end than I was just before the beginning. Should see if I can get the extra 8kph and start furthe back next year. I am ecstatic with my standing ¼ 11.17 and 233.99k on the flying, my speedo nearly reached 240kmh.

[MD]

I remember this being taught and I thought then as I do now, I'll never use this in real life.

Mike

BTW It was me who stopped the Harley Rider.

YOU REMEMBER STUDYING THIS ! My brain is like an iron clad vault, information goes in and it is bagged, tagged and securely filed away. I just can't remember where I put the key?
Mangell6 I got it right on my earlier post. I said it was you who stopped the Harley. Well done.
Speedo error. For what it's worth I was reading 299 just as I reached the first timer and each run averaged 281 point something. So that's not too far out at 6%, although the speedo is limited at 299 (thanks to corporate social responsibility) so maybe it would have misread higher if allowed.
That black Commodore was there when we 'gently' rode past going home too. I'm sure he gave us the evil eye - why the hell are you Guys riding at 102kph !
MD

[Sparky Bills]

Thats not bad for a naked bike!
Did you feel like you were going to fly off the back like a parachute?

And if people were still accelerating at the end...
You should play with gearing. When would you be-able to use all the power if it takes ages to get up to full speed?
The faster you get there the better!
Makes for good wheelies too!

[Sparky Bills]

You have to catch me first Matty!
But your right!
EVERYONE MUST COME!!

[jimbo600]

YOU REMEMBER STUDYING THIS ! My brain is like an iron clad vault, information goes in and it is bagged, tagged and securely filed away. I just can't remember where I put the key?
Mangell6 I got it right on my earlier post. I said it was you who stopped the Harley. Well done.
Speedo error. For what it's worth I was reading 299 just as I reached the first timer and each run averaged 281 point something. So that's not too far out at 6%, although the speedo is limited at 299 (thanks to corporate social responsibility) so maybe it would have misread higher if allowed.
That black Commodore was there when we 'gently' rode past going home too. I'm sure he gave us the evil eye - why the hell are you Guys riding at 102kph !
MD

Was the mufti still on the main drag between Martinborough and Featherston or did he infiltrate towards the East West access rd?

[Velox]

BTW It was me who stopped the Harley Rider.

What did he/she/it have to say for themselves? Did they really not realise???

[StoneChucker]

You should play with gearing. When would you be-able to use all the power if it takes ages to get up to full speed?
The faster you get there the better!
Makes for good wheelies too!

How do you fiddle with the gearing?

And, will they let us start further back? You would have to zip through the cones at high speed?..?

Mangell6, thanks for stopping the harley rider. I would have loved to know what the rider I passed was thinking. Next year the Marshalls should carry rifles, and shoot to kill any would be dicers!

NOW, I HAVE a question. Why do the "Mark Dunn's" of KB go 281, and I only crack 260 (average of 1/4 mile). Is it just the extra say 30kgs I'm carrying, in, err, "fuel"? Will loosing this "fuel" get me up there with the "big boys", or do I have to fork out for exhausts, PC3, de-restricting kits, etc......

[Velox]

NOW, I HAVE a question. Why do the "Mark Dunn's" of KB go 281, and I only crack 260 (average of 1/4 mile). Is it just the extra say 30kgs I'm carrying, in, err, "fuel"? Will loosing this "fuel" get me up there with the "big boys", or do I have to fork out for exhausts, PC3, de-restricting kits, etc......

Nah - you just have to get a Honda.

[StoneChucker]

get a honda

Today starts your 1 month of the silent treatment