Recent content by Celunas

Very interesting question, I'm not sure that fields carry energy though, it's more about the interactions with the field, the field itself isn't energy (at least I think so). And from the interactions, energy can convert into mass, thanks to the field but I don't think there is a field energy...

I assume you can already use vectors (if not, I am not sure how I would do this question !) The air speed is calculated with the plane as a frame of reference. It means you forget about the ground. Try to imagine you're flying this craft. Forgetting the wind, due to your ground speed, you...

a) sorry I'm not familiar with baseball (and english isn't my native language), what do you mean by "clearing a fence" ? I assume you either mean that the baseball passes above, or hits the fence. Either way : The baseball is hit at the same height than the fence. The equation d= (v^2sin2x)/g...

Maybe it's just an error ! :)

the intensity of the compression of the air only changes the volume of the sound, while the frequency of the vibration changes the sound. It means that when you clap your curved hands, somehow the frequency of the vibration created is lower than with flat hands. I guess it has something to do...

In this case the only centripetal acceleration is the acceleration due to the gravity, there is no centripetal acceleration similar to the centrifugal acceleration (due to a virtual force).

The dot product of the work of a force is : vector F. vector d = F * d *cos (vector F,vector d) In fact a force can work only in the direction of the movement (for a linear movement and a constant force). So only the part of the force being in the direction of the movement (Fwx for instance)...

Indeed Redbelly98 that was my point. With this expression you find Fw. Then you can deduce Fwx ( Fwx = Fw * cos(32°) ) And once you have Fwx.. well, we won't give you the solution :)

I understand it that way : (sorry if I repeat something you said Doc Al) The string in the equilibrium position has a certain amount of elastic potential energy. We can take this equilibrium position's potential energy as a reference. You have to find the work done on the spring, so the...

Fwx and Fwy are just two projections of the Fw force, so you can write : Fwx = Fw*cos(32°) Fwy = Fw*sin(32°) Then your equation has only one unknown, you can find it out and use your result to calculate the work. ( just be careful to use Fwx and not Fw in the work's calculation)

It's weird I can't edit my post anymore :S I wanted to correct : I'm talking about Newton's second law of motion and not his third, but I'm sure everybody corrected by themselves :)

The fact is that due to Newton's third law, the sum of forces applying to a system equals it's mass*it's acceleration. Here we have 2 forces : the gravitational and the centrifugal forces. So we have mg - mv²/R = m a (using a centripete axis) Which yields immediately : a = g - v²/R So, in a...

I've heard (also on a TV show) that it's about energy vibrating. But personnally I prefer not to care and just think that the string theory physicists just handle mathematical descriptions of some sort of multi-dimensional oscillation that seems to be able to describe some physical reality (not...

Hello ! I don't know if it will help but I understand it that way : A wave function (what a sine function of space and time is) moves in space during time. If you take as a reference the time t where a certain point of this sine function (say, for a non-perfect sine function, a maximum...