ElectricPavlov

yes....

Density is usually in units of   kg/m^3   or perhaps   mg/cm^3

Volume is given in m^3 or perhaps cm^3

Mass would be given in kg or mg

If you multiply volume by density you will get mass

  example     m^3  * kg/m^3  = kg   

Dango.....we need the table....do you have it? 

F= -kx    where k = spring constant  x = stretch distance

F=ma = 2 kg x 9.8 m/sec^2 = 19.6 N

19.6 = - k (.0288 m)       k = - 680 N/m

I get 19.41 for the total perimeter  (sorry didn't see that in your last post).....

Learning is sometimes difficult....But all of a sudden it will go "CLICK" !.    Hang in there..

I'll show you how to do the first part of the perimeter....I'll do the longest side

  two points   (x1 y1) and (x2 y2)   are (-1,5) and (5,1)   right?   

Use the formula:  d^2 = (x1-x2)^2 + (y1-y2)^2

                                    = (-1-5)^2 + (5-1)^2

                             d^2 = (-6)^2  +  (4)^2 

                             d^2 = 36 + 16

                              d^2 = 52

                              d= sqrt(52) = 7.21 units   (for ONE side of the perimeter)

See how I did that?    Now you do it for the opposite side     (3,7)  and (-1,5)       Then we will be half way....

    try it and let me know what you get.....

Exactly !    7     Now you can calculate the areas of both of the triangles   (1/2 b * h )   then add them together....

Voila !    You have the area of the composite figure.......

Now let's start work on the perimeter.....

Distance between two points on the coordinate plane   d^2 = (x1-x2)^2 + (y1-y^2)^2     (remember?)

You might have to do it FOUR times for this figure....   Go!

This scan may be a bit clearer.....   Cowgirl Up !   as they say....don't stress...you can do this.....I am not going to do it for you, but I'll help you through it........it will become easier as YOU work tyour way through it.....go !

Very close.....but check that '6' dimension !   

Higher up in this thread I posted how to find the area of a triangle....

    there is actually only TWO triangles of concern in the scan I posted......the lines marked 'H' are just to show the dimensions for 'Height'......   You CAN do it......  And you don't need the perimeter to calculate the area....(though I do understand you have to find the perimeter per the question)