m= 1.2 x -0 kg *= 0. 15 12. A block of mass 2kg is moving at a speed of 4 m/s on a frictionless surface toward a spring. The spring has a spring constant of 20 N/m. (A) How fast is the block going when it has compressed the spring .05m? 2 2 kg ( 4 ) 2 = = 2kg v2+ 2 (20 ) (05)? m]-. (B) What is the maximum compression caused by the block? 2 + 2 15 ( : 08 ) 2 = 15 k ( 13. [Honors] A spring hangs at rest from a support. If you suspend a 0.46 kg mass from the spring it elongates 079m. (A) Determine the spring constant. X =0 Ax = 7.9 cm (B) Calculate the elongation ii you put a .75kg mass on the spring. a)