Wednesday, 23 November 2016

experiment on Hooke's Law



Hooke's Law experiment by Firas Baroum



       Hooke's Law : "when an elastic object - such as a spring - is stretched, the increased length is called its extension. The extension of an elastic object is directly proportional to the force applied to it"(1) ,  ( F = kx ) or as shown in (Figure 1) ( F = ke ) "This equation works as long as the elastic limit (the limit of proportionality) is not exceeded"(1) , where :

F : is the force in newtons, N
k : is the 'spring constant' in newtons per meter, N/m
x : is the extension in meters, m

an example of Hooke's Law is presented in (Figure 1) below :

(Figure 1)(1) 


as stated above the extension of the elastic object is directly proportional to its Force (2)




    The aim of the following experiment is to investigate the behaviour of three materials : y1 , y2 , and z in respect to Hooke's Law.

Table 1


      Considering the values of x and y1 to be as given in (Table 1) and using these three equation :       (y1 =  ax + b) eq1 , [y2 = (a + 0.5)x + c] eq2 and (z = x^3 +b) eq3 , where c = 0.2 .
a and b values were obtained from using x and y1 values in Excel and plotting them in (Table 1) ,
then subsitutting them in eq2 to complete the graph of y1 and y2 shown below (Figure 2)


(Figure 2) y1 vs x and y2 vs x

         Which enabled the use of the two simultaneous equation in (y1 = y2) to find the point where the two lines intersected : 1.5583x + 1.375 = 2.0583x + 0.2     =>               x = 2.35
and then substituting x in either y1 or y2 [ y2 = (2.0583*2.35) + 0.2 ]   y2 = 5.037
which mean that ( 2.35 , 5.037 ) is the point where the two lines intersected.

Finally using eq3 the graph of z versus x was plotted in (Figure 3) :


(Figure 3) z vs x


        In relation to Hooke's Law , x is the Force applied (Newton) where as y1 , y2 ,  and z are the deformation , and k is the gradient (F , x).

        y1 and y2 are two different elastic materials but they were both still in their linear elastic region (Figure 2) , also y2 is more elastic than y1 because they both had equal amount of x ( Force ) , but it had higher deformation than y1.
, where as z has gone past its elastic region to the ( plastic region ) which means it is no longer a linear elastic region (Figure 3).




       Errors :  probably the numerical value for x and y1 might haven't been that accurate that could possibly be because of reading/writing the wrong number when stating both of their values.
As well as while calculating the numbers in excel there is a chance of mistyping a number.



References/Sources :





"I am aware of the requirements of good academic practice and the potential penalties for any breaches".





No comments:

Post a Comment