I need help my newschoolers brethern who take physics

[jambone]

Assuming the ball has zero friction, its force of gravity is negligable as well as the initial speed of the block: At what angle will the block fall of the sideof the ball?

 

[Tinga]

the same angle at which it comes in

duh

 

[jambone]

the block is starting from the top of the ball

 

[gmack24]

it wont?

 

[Tinga]

oh well umm ... goodluck

 

[jambone]

it will fall off at angle between 0 and 90 degrees

 

[ATLskier]

i have no diea how to imagine that, and i take physics. I guess I'm just not there yet.

 

[Itsbackfliptime]

how could the initial velocity of the block be negligible?

 

[Tinga]

is the block moving or the ball

 

[jambone]

The block is sliding on the ball.

 

[jambone]

Since there is no friction just tape the block so its moving like 1/ one bajillionth of a millimeter per year and since there is no friction it will keep moving and sppeding up

 

[jambone]

ya i stumped u now

 

[Melvs]

if there is no frictiong, it will slide off the second the ball si not perfectly balenced. however, they tell you force of gravity is negliable, which means there is no force acting on the system. Therefore, if that's what teh problem really is, then it won't fall because there is no force acting on it.

 

[supervore]

melvs got it right, gotta have gravity for the block to fall

 

[jambone]

ya the gravity is still acting on the block but friction isn't

 

[vRoy]

^^I concur. That really is a dumb question, for the ball to 'fall' there needs to be a 'down'. down is defined by the direction of gravity, as there is none, the ball will go .... nowhere

 

[supervore]

if its perfectly balanced, it shouldnt fall off anyway...its been 4 years since i took physics, so i may be wrong...

 

[jambone]

Its my physics teacher hes dumb, but gravity is still acting on the ball just not friction

 

[Melvs]

if that is true, then as I said ebfore, with no friciton, teh ball will only have to tip the tinyest bit for ti to fall (an infinitly small amount).

that's the answer.

 

[jambone]

ya but at what angle will it fall off. It will start to slide down and at a set angle the ball will come off

 

[Hctiws_iks]

tricky stuff.

do do this you have to find what velocity in x directionstheir is per every delta x,

then you have to compare that with the times it has to clear evey delta x. whenever its starts with more than enough time you win.

 

[jambone]

now we're gettin on the right track

 

[jambone]

i'm not in calculus but what is 2(theta)=sin(theta)

 

[GotamaBCshredder]

it should come off in the exact opposite angle that it came in shouldn't it?

 

[Melvs]

if there is no friction, it will come of at the angle where the COM of the block is not directly over the point at which it touches the sphere. There is no need to bring any sort of calculus into this, it's a purely theoreitcal question.