Question 1 A 20 kg mass is fastened to a spring of force constant k= 350 N/m by a string passing over a light pulley. The spring is initially un-stretched. If the mass dropped from rest from 0.4 m height, then what is the mass's speed v (in m/s) just before it hits the ground? 0.4 m (00000] COOOOO after before O 2.45 O 2.28 O 2.53 O2.19 O 2.37 13 Activate Windows