Timmy drops a ball off the roof of a building. it falls for 3 seconds before hitting the ground. How fast is it going before it hits the ground? How tall is the building?

3. a lunar exploration vehicle was created by a research team. it weighs 3,000 kg on the earth. it needs an acceleration of 10 m/s2 on the moon. in order to have the same acceleration, what will be the net force acting on the vehicle on the earth?