A hot-air balloon is rising straight upward with a constant speed of 6.5 m/s . When the basket of the balloon is 20.0 m above the ground, a bag of sand tied to the basket comes loose and reaches a maximum height of 22 m .
Now, suppose the balloon is descending with a constant speed of 4.2 m/s when the bag of sand comes loose at a height of 35 m . What is the amount of time the bag is in the air?
What is the speed of the bag when it is 17 m above the ground?