
Aim: to find how to predict the Elastic Constant of
combinations of springs 
The elastic constant of a spring tells us the number
of Newtons force needed to extend (or compress) it by a
given amount (usually the number of
Nm^{1} or
Ncm^{1}). 
See elastic constant of spring. 

Method 
Measure the elastic constants,
k_{1} and k_{2} of two springs. 
Make sure that you choose
springs having significantly different elastic
constants. 
Repeat the experiment with the
two springs "in series", as shown below. 

Obtain results from which can be found the value of
the elastic constant, k of the two springs together. 

Similarly, try to measure the value of k
corresponding to the two springs placed "in parallel"
with each other as shown in the next diagram. 


This might be a bit more tricky in practice but
should be possible with certain pairs of springs... 

When you have results of forces and extensions, plot
graphs from which the various values of elastic
constants can be found. 

Starting from the equation which defines the elastic
constant 

find a mathematical relation between k, k_{1}
and k_{2} for each of the combinations of
springs. 
See if your experimental results verify this
relation. 



