If a bird is moving at a velocity of 70 km/h east and a car is moving at a velocity of 80 km/h east, what is the velocity of the bird relative to the passengers in the car? \ a. 10km b. 10km/h c.10km/h west d.70 km/h east

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)