The Machine

1. if T_ij = −T_ji and S_ij = S_ji, then T_ijS_ij = 0.

2. Show that if epsilon_ijkT_jk = 0 then T_ij = T_ji.

Let T be a second-order tensor. Prove that Tkk is an invariant. Please.

http://postimg.org/gallery/9rqaakuk/

d(v^2/2) + dp/(rho) = 0 for an isentropic process where p / (rho)^gamma = constant.

Explain the result.

Please help

How does air compressor air compare with the ambient air. I know water comes out when the air is compressed. Is the compressed air considered "dry"?

a solution to the partial differential equation:

c^2 * d^2 u / dx^2 - d^2 u / dt^2 = 0.

Justify your answer. You will need to use chain rule.

Thanks!

I don't know where to start...

the solution manual says the answer is (pi - arcsin(3cos^2(x))) / 3. I got the arcsin(3cos^2(x)) / 3 part of it, but I don't understand the pi or the (-) sign. Please help?

also, it says the interval that the solution is defined is abs(x-pi/2) < 0.6155. can you explain this to me?

Two cases are presented where a uniform square of side length, L, are allowed to fall from being balance on a corner, point O, to the edge. In case one, the block will rotate on a frictionless hinge. In case 2, the block will slide on a frictionless surface as it falls. The block has mass, m. The center of mass is positioned slightly to the right of being above O, so the blocks will fall in a clockwise direction.

For both cases:

1. With what velocity does the corner hit the ground?

2. What is the angular velocity of the block just before impact?

Exactly!!! but my professor seems to think it does as he added that question to the review sheet.

A uniform rectangular sign is supported by two horizontal beams that are fixed to the top and bottom corners on the right edge (points a&b). The sign has a mass of 5kg. It is 0.5m tall and 0.8m wide. Find the loads acting on point a and point b.

Sum forces x = Fax + Fbx = 0

Sum forces y = Fay + Fby - mg = 0

Sum moments about a:

0.4mg + 0.5Fbx = 0

Fbx = (0.4*5*9.81) / (-0.5)

Fbx = -39.24N

Therefore, Fax = 39.24N

The problem is I can't seem to find the reaction forces in the y direction because i don't know where to take the moment. Please help

Two strings are hanging vertically from the ceiling and are attached to the ends of a massless rod, which is horizonal. there are two point masses that are positioned on the rod.

If one of the supporting strings is cut would the tension in the uncut string immediately after the cut be smaller if both masses are positioned in the center of the rod or if one is on each end?

two strings are hanging vertically from the ceiling and are attached to the ends of a massless rod, which is horizonal. there are two point masses that are positioned on the rod.

If one of the supporting strings is cut would the tension in the uncut string immediately after the cut be smaller if both masses are positioned in the center of the rod or if one is on each end?

So I'm supposed to write a program that uses the following functions:

Fill_array() takes as arguments the name of an array of double values and an array size. It

prompts the user to enter double values to be entered in the array. It ceases taking input when

the array is full or when the user enter a negative number, and it returns the actual number of

entries.

Show_array() takes as arguments the name of an array of double values and an array size and

displays the contents of the array.

Reverse_array() takes as arguments the name of an array of double values and an array size and

reverses the order of the values stored in the array.

The program should use these functions to fill an array, show the array, reverse the array, show

the array, reverse all but the first and last elements of the array, and then show the array.

Here is what i have so far:

#include <iostream>

using namespace std;

int fill_array(double *pt,int size);

void show_array(double *pt, int size);

int reverse_array(double *pt, int size);

int main()

{

double amat[10];

int n;

n = fill_array(amat,10);

show_array(amat,10);

n = reverse_array(amat,10);

show_array(amat,10);

char x;

cout << "\nPress any key and Enter to exit";

cin >> x;

return 0;

}

int fill_array(double *pt,int size)

{

int i;

cout << "Enter " << size << " values\n";

for(i=0;i<size;i++)

{

cin >> pt[i];

}

return i;

}

void show_array(double *pt,int size)

{

int i;

cout << "\n\nArray values:\n";

for(i=0;i<size;i++)

cout << pt[i]<< "\t";

return;

}

int reverse_array(double *pt, int size)

{

int i;

int swap;

for(i=0;i<--size;i++) //increment i and decrement size until they meet each other

{

swap=pt[i];

pt[i]=pt[size];

pt[size]=swap;

}

return i;

}

The main problems that I have is that I don't know how to make the array stop taking values when a negative number is entered and I don't know how to do the last thing where it wants me to keep the first and last number but reverse the others.

Please help.

Ok. I'm given two masses stacked on top of one another with the coefficients of static and dynamic friction between the two blocks and between the bottom block and the floor. I'm also given the dimensions of the blocks (not sure why that matters). I'm given that a force is applied to a corner on the upper block. However, I am not given the mass of either block. How do I solve for the acceleration of each block?