PHYSICS!!!

[sbcanada]

If any of you are good at physics, try your luck at this one, I need a solution, not just the answer.

 

[sbcanada]

Helpful things:

Energy Before = Energy After

Accelleration due to gravity: 9.81m/s

I think we're supposed to find it's potential energy at Point A, and it's Potential energy at Point C, and subtract the potential energy at Point A from Point C to get the Kinetic energy at Point C, which is somehow changed into speed...

 

[sbcanada]

If no one has time to try to answer it but you know something about Physics, tell me...

How do I covert Joules of Kinetic energy into speed (m/s)?

 

[Ponch]

m.g.(h3-h1) = (m.v^2 )/2.
---> v=sqr( 2. g . (h3-h1)).

 

[sbcanada]

 

[sbcanada]

Don't you mean:

v=sqr( 2. g . (h1-h3)) ?

 

[sbcanada]

Using the equations that I've learned... I find that the Kinetic Energy at Point C is 78.48 Joules. Now, How do I convert that to speed in m/s? ?(

 

[Ponch]

You can't find the Energy of that thing if the mass is unknown.
Take my formula, you have m/s.

 

[sbcanada]

I can find the energy if the mass is unkown. My teacher said so. Because "the mass cancels out on each side of the equation."

Whatever the fuck she's talking aboot, eh?

Is it possible to determine speed with the kinetic energy?

 

[Ponch]

Originally posted by sbcanada
I can find the energy if the mass is unkown. My teacher said so. Because "the mass cancels out on each side of the equation."

Whatever the fuck she's talking aboot, eh?

Is it possible to determine speed with the kinetic energy?

the mass cancels out on each side of my equation, there for I can find the speed.
What's your's ?
I repeat, you can not find the energy cause you don't have the Mass. I you think you have the energy, then you pretend you can find out the mass of the object too, just from the drawing...which is obviously not the case.

 

[MuFu]

Basically the change in gravitational potential energy going from A to C = the kinetic energy at C.

delta GPE = KE@C
12mg - 4mg = (1/2)mv^2
(m's cancel)
8g = (1/2)v^2
v = sq rt. (16 x 9.81)
v = 7.67ms^-1

Is that right? I dunno... haven't done this kinda shit in ages. Sorry if I just added to the confusion. Good excuse to use the one-fingered bowling ball though:



MuFu.

 

[MuFu]

How come you're doing that kinda physics at 18? ?(

MuFu.

 

[ihcra]

didnt you?

 

[MuFu]

Nope. It would be GCSE or lower here in the UK (same as US). So 14-15 years old.

Helping out a younger mate with their physics homework, sb?

MuFu.

 

[outside looking in]

Heh, I didn't do that kind of physics until freshman year of college.

That's ok though, cauz I aer smart nough.

 

[MuFu]

Originally posted by outside looking in
That's ok though, cauz I aer...

Wow. Finally a confession.



MuFu.

 

[outside looking in]

Originally posted by MuFu

Originally posted by outside looking in
That's ok though, cauz I aer...

Wow. Finally a confession.



MuFu.

 

[ris]

another aer!! the disease spreads.....