A 0.50kg mass hangs from a light spring of force constant 20N/m fixed to the ceiling. With the spring initially at its natural length, the mass is pulled downward so the spring stretches an additional 0.30m. At that instant the mass is given a downward speed of 1.0m/s. What is the speed of the mass when the spring is stretched only 0.10m beyond its natural length? (Assume the downward direction is positive and neglect air resistance.)
a) 1.9m/s
b) 3.5m/s
c) 2.8m/s
d) 0.53m/s