# Search results

1. ### Separation vector

Let c' be the separation vector from a fixed point(x'',y'',z'') to the point (x,y,z) and let c be its length. show that Gradient(1/c) = -c'(hat)/c^2 Thnaks for the help
2. ### Cross Product

AX(BXC) = B(A(dot)C) - C(A(dot)B) For the left hand side I got (AyBxCy-AyByCx+AzBxCz-AzBzCx)x(hat) + (-AxBxCy+AxByCx+AzByCz-AzBzCy)y(hat) + (-AxBxCz+AxBzCx-AyByCz+AyBzCy)z(hat) Is this right? Where would I go from here to prove the rest? Thanks for the help
3. ### Matlab Kinematics question

I know this is a programming language question, but no one seems to answer in that Forum. I'm running a program in Matlab and I'm running two loops One for the velocities in the x,y,z components and another for the magnus force (spin) vx,vy,vz. I'm holding all constant except vy and vz which I...
4. ### Need help with this Spiral problem

The spiral has a center in the yzx axis (it is like a coil but flat so the radius gets bigger) You can do this by polar coordinates (I was told), but I do not know how. I need to find a vector field that is directed along the x axis. And alpha is the angle subtended by a radius at the point on x.
5. ### From r to R e^(-2r/a)*r^2 dr

from r to R e^(-2r/a)*r^2 dr Thanks
6. ### Need help with this Spiral problem

alpha; which is the angle subtended by a radius at the point of observation (x).
7. ### Need help with this Spiral problem

There is a spiral but it is just on the yz plane (no length to it) I need to integrate it. And I'm at a location x on the axis if it matters. Thanks
8. ### Satellite orbit

When a satellite is in a circular orbit around the earth how does a rocket thrust from the satellite effect the orbit. Example when the rocket is fired toward the earth and another example when the rocket is fired orthogonal to the plane of the orbit. Thank you
9. ### Coupled Oscillations

I have a system that consist of the first spring attached to a ceiling and a first mass is attached to this spring. Then a second spring is attached to this first mass. Finally I have another mass attached to the second spring. So all of it is just hanging down. (I hope this is a good enough...
10. ### Standing Waves

A string 3.2 m long and with a linear mass density of .008 kg/m is kept under tension so that traveling waves propagate at 48 m/s along the string. The ends of the string are clamped and the string vibrates in its third harmonic with an amplitude of 5.0 cm. How much energy is stored in this...
11. ### MATLAB Matlab with physics

How would I write a program to show the kinetic energy, potential energy and total mechanical energy at each position in a orbit. I'm not given mass within the program I have to modify I wanted to just use .5mv^2 = k -GMm/r = p and E = k + p but can not due to no mass
12. ### Orbital motion question

I got it! Thank you arildno
13. ### Orbital motion question

escape velocity to me means the speed it takes to overcome gravity (air friction negligible) leaving orthogonal from the surface of the planet
14. ### Orbital motion question

Are you talking about U(r) = -GMm/r The bigger the radius the smaller the potential energy Ve = square root ( 2GMe/Re) = square root(2gRe) Is this what you are talking about?
15. ### Orbital motion question

Show that the escape speed from a planet is related to the speed of a circulat orbit just above the surface of the planet by Ve = square root(2Vc), where Vc is the speed of an object in the circular orbit. I'm looking at GMem(object)/r^2 = m(o)v^2/r But I do not know if this equation will...
16. ### Newton's law of gravity

Two particles having masses of m and M respectively, attract each other according to Newton's law of gravity. Initially they are at rest at an infinite distance apart. Find their relative acceleration and show that their relative velocity of approach is v(rel) = square root(2G(M+m)/a)...
17. ### MATLAB Need Matlab help

What does it mean when it says error: Vectors must be the same lengths
18. ### Need useful information on Mech. Eng.

but another opinion, and I thank you for it.
19. ### Need useful information on Mech. Eng.

I want advice (since universities all want to say the same thing). I want to invent products. I already have a list of products not yet marketed, I talked to my physics professor's and they told me Mechanical Eng. would be the closes for this goal. Anybody with experience in this field please...
20. ### Equation of a plane orthogonal to a vector

I had to leave to fast I just want to say thank you for all your help arildno
21. ### Equation of a plane orthogonal to a vector

yes, but this is due in another twenty minutes if you do not mind could you walk me through the steps. Another thing this is a physics assingment, but I placed it in the math due to it being math oriented. I took intro to linear algebra and I realize that in linear algebra it has to be more in...
22. ### Equation of a plane orthogonal to a vector

yes I'm following now
23. ### Equation of a plane orthogonal to a vector

I'm not understanding #5
24. ### Equation of a plane orthogonal to a vector

a plane parellel to the normal vector b
25. ### Equation of a plane orthogonal to a vector

A plane i think
26. ### Equation of a plane orthogonal to a vector

yes I agree, and I tried to go further to see if I could work something out but still no lightbulb yet
27. ### Equation of a plane orthogonal to a vector

yes I agree due to the dot product rule
28. ### Equation of a plane orthogonal to a vector

yes I'm up to equation 4
29. ### Equation of a plane orthogonal to a vector

Yes! yes! I follow now and I went back to post 17 and followed all the way through to equation 4. (I hope this was the way to go)

yes I agree