physics year 12 - topic 1 (2 Viewers)

[jnney]

Newton’s concept of escape velocity was that if a body is launched from a very high building, as the velocity of horizontal launch is increased, the body’s rate of fall would match the Earth’s curvature. The escape velocity was equal to the horizontal velocity needed for the body to stay in orbit. If the object was launched at a speed less than this then the object would return back to Earth and if it was launched with a speed greater than this then it would go off into space and never return to Earth.

can someone please explain to me what this means?

 

[hayabusaboston]

What, you mean like conceptually? Physically? Mathematically?

 

[hayabusaboston]

Okay well for the horizontal velocity required to stay in orbit; it equals the escape velocity as the escape velocity is achieved when an object no longer is under the full influence of gravity, and if it's in orbit (Having a high enough horizontal launch velocity) then it is not being controlled by gravity, rather it is tapping into Earth's gravity to maintain a horizontal 'fall' around and around the earth...? DOnt know if that makes sense, sorry I'm not much of a teaching person. So basically it has escaped the earths pull to the centre of earth, hence the escape velocity, and it is in the exact position where it is just tapping onto the earth's gravity for a horizontal fall.....

HEY here's a better explanation,
Horizontal velocity to maintain orbit IS escape velocity. One equals the other, they are just different mathematical scenarious depending on your context.

 

[interesting]

The escape velocity = horizontal velocity needed for the body to stay in orbit.. simply put, the velocity or barrier in which the object is able to JUST stay under the influence of gravity which allows it to stay in orbit around the Earth is the ESCAPE VELOCITY. So it like hasn't fully escaped earths gravity or else it'd travel off into space , and isn't falling back to Earth either

 

[hayabusaboston]

The escape velocity = horizontal velocity needed for the body to stay in orbit..
lol it's pretty much what it says?

Yea, that's what it says. Now to explain it to Jnney. I can't, so you try, interesting

 

[applepie1234123]

Yea, that's what it says. Now to explain it to Jnney. I can't, so you try, interesting

Physics confuses me

 

[Alkanes]

Oh thank the lord i am dropping physics. =D

 

[hayabusaboston]

Ach man. Jnney I dont know did I make sense? I wasn't sure what type of answer you were looking for or in what depth.

 

[jnney]

The escape velocity = horizontal velocity needed for the body to stay in orbit.. simply put, it is the velocity or barrier in which the object is able to JUST stay under the influence of gravity which allows it to stay in orbit around the Earth. So it like hasn't fully escaped earths gravity or else it'd travel off the Earth

But then isnt 'escape velocity' defined by the launch velocity required to escape the gravitational pull of a particular planet in that it never returns again? that's what im confused about. it seems...conflicting.

 

[interesting]

But then isnt 'escape velocity' defined by the launch velocity required to escape the gravitational pull of a particular planet in that it never returns again? that's what im confused about. it seems...conflicting.

ermm what, launch velocity, isn't that the velocity needed to escape the gravitational pull? Escape velocity is the velocity required to rise vertically and just escape the gravitational field of a planet..

 

[jnney]

oh dw about, launch is not meant to be there

 

[will_]

im pretty sure escape velocity is a vertical velocity required not horizontal

 

[interesting]

im pretty sure escape velocity is a vertical velocity required not horizontal

yeah its vertical

 

[Fizzy_Cyst]

It should say The orbital velocity was equal to the horizontal velocity needed for the body to stay in orbit.

not escape velocity, they are two completely different concepts.