When helium is released from a compressed container, the decompressed atoms expand and rise, causing the rubber balloon to inflate and float along. In this scenario, helium exists in a gaseous state.
The rocket's acceleration is described here as

now recognizing that

we integrate both sides



given that the rocket is accelerating for a duration of t = 10 s
thus, we have


consequently, after t = 10 s, the rocket will achieve a speed of 130 m/s in an upward direction