We can calculate the length of each spring by using the relationship:
[tex]F=kx[/tex]
where
F is the force applied to the spring
k is the spring constant
x is the length of the spring (measured with respect to its rest position)
Re-arranging the equation, we have
[tex]x= \frac{F}{k} [/tex]
The force applied to both spring is F=60 N. Spring A has spring constant of k=4 N/m, therefore its length with respect to its rest position is
[tex]x_A= \frac{F}{k_A}= \frac{60 N}{4 N/m}=15 m [/tex]
Spring B has spring constant of k=5 N/m, so its length with respect to its rest position is
[tex]x_B= \frac{F}{k}= \frac{60 N}{5 N/m}=12 m [/tex]
Therefore, the correct answer is
D.Spring A is 3 m longer than spring B because 15 – 12 = 3.
