Answer:
a. 140 N/cm
Step-by-step explanation:
The relationship between force applied, spring constant and compression/stretching of a spring is
![F=kx](https://img.qammunity.org/2020/formulas/physics/high-school/ivnw6jqhdmurxa3c0z25q7hl9zxvo5d7qf.png)
where
F is the force applied
k is the spring constant
x is the compression/stretching
In this problem, we have:
x = 0.250 m is the compression
F = 35 N is the force applied
Substituting and re-arranging the equation, we find the spring constant:
![k=(F)/(x)=(35 N)/(0.250 cm)=140 N/cm](https://img.qammunity.org/2020/formulas/physics/high-school/y4e49ppwbak7x09brf9esvppv2ce3uk2xl.png)