Earth spinning

mollymoo

mollymoo

mollymoo

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Just been thinking about a jetlag free air service to Australia, which led me to think of the earths rotation and its effect on travel, which then led me to a question on the world record for long-jumping.

If a long-jumper was to jump in a westerly direction could this add length to the jump due to jumping in the opposite direction of the earths spin?
Or would it make absolutely no difference?
 
It's all relative.
No difference - the jumper, the pit, the air - all moving at the same speed as the earth's rotation

It's like if you jump on a bus travelling at a constant velocity - you don't immediately fly to the back!
 
tres said:
It's all relative.
No difference - the jumper, the pit, the air - all moving at the same speed as the earth's rotation

It's like if you jump on a bus travelling at a constant velocity - you don't immediately fly to the back!
Click to expand...

They aren't though are they, when the jumper jumps in a westerly direction the pit is travelling easterly at a fair rate of knots, all I wondered is if the jumper is travelling eastwards at the moment before take off then will this drag them backwards with the earth therefore not affecting the jump or will they overcome that and end up jumping further due to the earth moving under them, a bit like jumping carriages on a train, much harder going in the direction of the train than going towards the back.
 
mollymoo said:
Just been thinking about a jetlag free air service to Australia, which led me to think of the earths rotation and its effect on travel, which then led me to a question on the world record for long-jumping.

If a long-jumper was to jump in a westerly direction could this add length to the jump due to jumping in the opposite direction of the earths spin?
Or would it make absolutely no difference?
Click to expand...

I was going to say you have way too much time on your hands, but then im sat at my work desk having a cup of tea, eating ginger nuts (biscuits, not testicles!) and browsing a forum :).
 
mollymoo said:
They aren't though are they, when the jumper jumps in a westerly direction the pit is travelling easterly at a fair rate of knots, all I wondered is if the jumper is travelling eastwards at the moment before take off then will this drag them backwards with the earth therefore not affecting the jump or will they overcome that and end up jumping further due to the earth moving under them, a bit like jumping carriages on a train, much harder going in the direction of the train than going towards the back.
Click to expand...

I think you mis-understand the physics of this...

Whilst he may travel further from the reference point of someone looking down from a fixed point in space, in relation to the earth, he was always travelling at the same rate at the beginning and end of the motion.

Or to simplify it... If you are on a train with a long corridor, and you run with or against the direction of travel, and jump... To someone sat outside the train looking in, the distance you travel will seem to be really short, or really long. But to the person sat on the train in the same point of reference it will still look like a normal jump distance.
 
The Earth's rotation has no effect on a long jumper for the reasons already mentioned, the ground and the jumper are moving in the same direction and the same speed.

Effects from the rotation of the Earth (coriolis effects) come into play over much larger distances, such as firing a long range cannon, as the earth spins faster at the equator and slower the closer you get to the poles.
 
If an aeroplane was sat on a treadmill that was moving in the opposite direction at the same speed the wheels were moving, would it be able to take off?







;)
 
Malt_Vinegar said:
I think you mis-understand the physics of this...

Whilst he may travel further from the reference point of someone looking down from a fixed point in space, in relation to the earth, he was always travelling at the same rate at the beginning and end of the motion.

Or to simplify it... If you are on a train with a long corridor, and you run with or against the direction of travel, and jump... To someone sat outside the train looking in, the distance you travel will seem to be really short, or really long. But to the person sat on the train in the same point of reference it will still look like a normal jump distance.
Click to expand...

spp said:
The Earth's rotation has no effect on a long jumper for the reasons already mentioned, the ground and the jumper are moving in the same direction and the same speed.

Effects from the rotation of the Earth (coriolis effects) come into play over much larger distances, such as firing a long range cannon, as the earth spins faster at the equator and slower the closer you get to the poles.
Click to expand...

Ok I'll get back to my jetlag free air service then thanks.
 
Ok, I've got a question.

If you're driving in a car at 30mph with the windows open. A bird (or RC plane), flying at exactly the same speed of 30mph next to the car, alters it's path and moves into the car.

1 - Would it suddenly fly forwards if the window was kept open?
2 - Would it suddenly fly forwards if you closed the window?
3 - What the hell would happen?
 
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Malt_Vinegar said:
Please don't start that one!

Yes, it will fly... Please no one else suggest anything else!
Click to expand...

This is the popular (and completely wrong :p ) counter argument

plane.png
 
ScarySquirrel said:
Ok, I've got a question.

If you're driving in a car at 30mph with the windows open. A bird (or RC plane), flying at exactly the same speed of 30mph next to the car, alters it's path and moves into the car.

1 - Would it suddenly fly forwards if the window was kept open?
2 - Would it suddenly fly forwards if you closed the window?
3 - What the hell would happen?
Click to expand...

It would stall, as there would be no wind over the wings to provide lift.
 
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