What is the maximum walking speed of an adult man whose legs are each 1.2 m long? A) 3.4 m/s

B) 12 m/s

C) 3.6 m/s

D) 7.9 m/s

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)