Ok you clicked this thread so i hope you know the formula for frequency/kinetic energy, Now I have to solve a word problem like this:
K-Energy: An object has a mass of 5 kilograms, and its velocity is 45ms². Calculate the kinetic energy for this object.
Frequency: Theres a wavelength of 0.050m, and wave speed of 25ms
−1. Find the frequency.
Please help/explain. my teacher just gives it to us straight out, and expects us to figure it out on the spot.
Ek = (1/2)mv^2
Ek = (1/2) x 5kg x (45m/s^2)^2
[without units = Ek = (1/2) x 5 x (45)^2]
Ek = Answer
The other one is potential energy which gets converted into kinetic energy when in motion.
Mechanical energy always stays the same (Ek + Ep) < the ratio between potential energy and kinetic energy changes though.
(12-05-2010, 07:54 PM)Infinity Wrote: [ -> ]Ek = (1/2)mv^2
Ek = (1/2) x 5kg x (45m/s^2)^2
[without units = Ek = (1/2) x 5 x (45)^2]
Ek = Answer
The other one is potential energy which gets converted into kinetic energy when in motion.
Mechanical energy always stays the same (Ek + Ep) < the ratio between potential energy and kinetic energy changes though.
Wow Infinity, you are one smart mother@#cker... Teach me your ways, lol jk, but ya you just find the formula, square the mass, and plug in. I haven't done equations like this in forever.
(12-05-2010, 08:42 PM)null_trace18 Wrote: [ -> ]Wow Infinity, you are one smart mother@#cker... Teach me your ways, lol jk, but ya you just find the formula, square the mass, and plug in. I haven't done equations like this in forever.
Yeah, no kidding. I would of had no clue how to do this.
lol thanks, I still remember my physics, I have a physics degree that is almost useless to me right now anyway.
didn't know there was a second question, lol I missed that..
Here we use lambda for the wavelength, velocity as indicated by "v" in m/s, and "f" is the frequency in Hz. I wasn't sure if you meant 25m/s to the power of -1, but if you did, you can probably just sub in the number for yourself in my equation. I used the MathType tool to create the formulas and equation.
![[Image: physics.png]](http://b.imagehost.org/0505/physics.png)
Gave you a cool visual as well
KE = 1/2mv^2
M = Mass
V = Velocity
(12-06-2010, 08:21 AM)Infinity Wrote: [ -> ]lol thanks, I still remember my physics, I have a physics degree that is almost useless to me right now anyway.
didn't know there was a second question, lol I missed that..
Here we use lambda for the wavelength, velocity as indicated by "v" in m/s, and "f" is the frequency in Hz. I wasn't sure if you meant 25m/s to the power of -1, but if you did, you can probably just sub in the number for yourself in my equation. I used the MathType tool to create the formulas and equation.
Gave you a cool visual as well
gimme your brain and/or become my maths and physics tutor. kthx
(12-12-2010, 05:45 PM)God Wrote: [ -> ]gimme your brain and/or become my maths and physics tutor. kthx
This is easy stuff, it gets a lot more complicated when you reach the level of equations for black holes and other things like that.