The hydrogen and helium under the clouds of jupiter are in liquid form due to
a. low temperatures on the planet
b. high temperatures on the planet
c. low pressure produced by the clouds
d. high pressure produced by the clouds

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)