How much would a spring scale with k = 120 N/m stretch, if it had a 3.75 J of work done
on it?

0.25m

Explanation:

Given parameters:

Spring constant , K  = 120N/m

Work done  = 3.75J

Unknown:

magnitude of extension = ?

Solution:

To solve this problem;

           Work done  = kx²  

K is the spring constant

x is the extension

               3.75  =   x 120x²

               3.75  = 60x²

                x²  = 0.06

                x = √0.06  = 0.25m

true tan speed = ang vel x radius