Answer:
0.48 m
Explanation:
I'm assuming that this takes place in an ideal situation, where we neglect a host of factors such as friction, weight of the spring and others
If the mass is hanging from equilibrium at 0.42 m above the floor, from the question, and it is then pulled 0.06 m below that particular position. This pulling is a means of adding more energy into the spring, when it is released, the weight compresses the spring and equals its distance (i.e, 0.06 m) above the height.
0.42 m + 0.06 m = 0.48 m
At the highest point thus, the height is 0.48 m above the ground.
