Below is depicted a block on a frictionless surface. It is attached by a spring to a wall. The unstretched length of the spring is 1.00 m. The spring is stretched so that its length as depicted in the diagram is 1.20 m. Because of the spring, the block is accelerating rightward at 2.3 m/s2. What is the force constant (also known as the spring constant) for the spring?
A. 20 N/M
B. 2.0 N/M
C. 50 N/M
D. 4900 N/M