# 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. ### From r to R e^(-2r/a)*r^2 dr

from r to R e^(-2r/a)*r^2 dr Thanks
5. ### 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
6. ### 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
7. ### 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...
8. ### 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...
9. ### 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
10. ### 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...
11. ### 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)...
12. ### MATLAB Need Matlab help

What does it mean when it says error: Vectors must be the same lengths
13. ### 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...
14. ### Newton's Third Law

If there was a block on a table what would be the normal force between the block and the table. If you could describe the free body diagram that would be great too.
15. ### Equation of a plane orthogonal to a vector

Let vectorB be a vector from the origin to a point D fixed in space. Let vectorW be a vector from the origin to a variable point Q(x,y,z). Show that vectorW (dot) vectorB = B^2 is the equation of a plane perpendicular to vectorB and passing through D. Thank you for any help
16. ### Vectors and Scalars

vector U is an unkown vector; known vectors are vectorA and vectorB and scalarF. vectorA (cross) vectorU = vectorB and vectorA (dot) vectorU = F. Express vectorU in terms of vectorA, vectorB, scalarF and the magnitude of vectorA. Thank you