Sink A Few And Then Watch This ...

[Airgead]

Bout 9 to 10 seconds i rekon sans parachute and with tool bag attached.

Worked it out...10.3 seconds ignoring air resistance and working off a tower height of 520m. Not quite long enough for a phone call but more than long enough to wish you'd clipped that safety line on.

 

[MarkBastard]

Wouldn't you fall at the same speed with the toolkit or without (ignoring wind resistance)

 

[Airgead]

Wouldn't you fall at the same speed with the toolkit or without (ignoring wind resistance)

Yep.

 

[Eater]

At "terminal velocity" i think you would be the same, but wouldn't the initial acceleration towards that speed be faster with more weight? In my mind more so if the weight is at the end of a tether some way below you (not sure why i think that just do)
(no i have never done a physics class, im just asking a question)


Either way, if you listen closely to the video you can here a sound as if two large brass objects are clanging together....

 

[JonnyAnchovy]

At "terminal velocity" i think you would be the same, but wouldn't the initial acceleration towards that speed be faster with more weight? In my mind more so if the weight is at the end of a tether some way below you (not sure why i think that just do)
(no i have never done a physics class, im just asking a question)

Don't think so. I don't think weight affects how fast objects fall - it's all just wind resistance.

 

[MarkBastard]

Yeah, acceleration due to gravity is a constant I thought. There is no weight variable in the formula. I do believe however there is a weight point where if you go light the equation does change, but that may be just a simplistic way of saying small objects are affected by the atmosphere, wind etc more.

 

[Airgead]

Yeah, acceleration due to gravity is a constant I thought. There is no weight variable in the formula. I do believe however there is a weight point where if you go light the equation does change, but that may be just a simplistic way of saying small objects are affected by the atmosphere, wind etc more.

Yep. Ignoring air resistance a feather and a cannonball will hit the ground at the same time. In air of course the feather has higher air resistance and falls s;lower so this only holds true in a vacuum. There's a really cool film of one of the Apollo astronauts doing the experiment on the moon. A hammer and a feather hit right at the same time.

Wind resistance will slow things down for a person falling (by how much depends on whether they are going head first or spread out) but not my much. The tool bag won't make much difference except maybe to pull you into a feet down position which will fall faster than a spread oput one.

Anyway. About 10 seconds. Which is way too long a time to watch the ground coming up at you and knowing there's nothing you can do about it.

Cheers
Dave

 

[Ducatiboy stu]

The last thing to go thru his mind would be his ass

 

[fraser_john]

hehe just sent the link to my missus that is deadset scared of heights, I'll probably get abused for it.

Cannot believe how slack they are about that safety clip.

 

[mika]

blah, blah, blah, bunch of science stuff.

I'm just trying to get my head round this. Searched on the net, but couldn't find an answer that made sense.
It's my understanding that where there's a change in 'height', there's a change in Potential Energy. As energy can be neither created nor destroyed, only converted, the Potential energy becomes Kinetic Energy.
Working with, PE=mgh, KE=1/2mv^2.
How does the mass portion of the PE equation tie in with the Galileo findings. I've seen explanations, it just doesn't make sense to me at the moment.

 

[Airgead]

I'm just trying to get my head round this. Searched on the net, but couldn't find an answer that made sense.
It's my understanding that where there's a change in 'height', there's a change in Potential Energy. As energy can be neither created nor destroyed, only converted, the Potential energy becomes Kinetic Energy.
Working with, PE=mgh, KE=1/2mv^2.
How does the mass portion of the PE equation tie in with the Galileo findings. I've seen explanations, it just doesn't make sense to me at the moment.

Ahhhh... first let me say that I'm not a physicist. Just an amateur smartarse...

The feather and the cannonball will have very different kinetic energies when they hit - drop on of each on your foot and you will see. But their velocities will be the same. When they are raised up, they each have different potential energies as their mass is different. Gravitational potential energy has a mass term in the equation. So conservation of energy is satisfied.

The thing that is mass independent is the acceleration due to gravity which is the same regardless of mass.

So different masses fall at the same velocity. Different masses have different potential energies at the same height.

I can dig the equations out if that will help.

Cheers
Dave

 

[MarkBastard]

Think of a tonne of bricks falling from the air. If they were bonded together or floating apart why would the ones bonded together fall any faster? It's not like the lower bricks pull the upper bricks down with them.

 

[mika]

Ahhhh... first let me say that I'm not a physicist. Just an amateur smartarse...

The feather and the cannonball will have very different kinetic energies when they hit - drop on of each on your foot and you will see. But their velocities will be the same. When they are raised up, they each have different potential energies as their mass is different. Gravitational potential energy has a mass term in the equation. So conservation of energy is satisfied.

The thing that is mass independent is the acceleration due to gravity which is the same regardless of mass.

So different masses fall at the same velocity. Different masses have different potential energies at the same height.

I can dig the equations out if that will help.

Cheers
Dave

No, think that makes sense now.
Just couldn't get my head around it before.
Cheers !