I'm not sure if a figure or some choices go along with this, but the closer to the sea floor the diver is, the lower the potential energy
The change in velocity from 30 m/s north to 40 m/s south is a change of 70 m/s south
The best scenario to describe the doppler effect would be listening to the siren of a passing ambulance or fire truck
then it is coming towards you, the pitch is higher, it gets higher as it approaches and peaks as it gets right in front of you. then it drop at once when it passes you and continues to drop till it fades away. this is a classic descrption of the doppler effect
Force equals mass times acceleration. Or:
F=ma
Plug it in:
5=10a
5/10=(10a)/10
.5m/s²=a
W = m.g = weight
g = Gme/Re**2 where G= universal gravitational constant , Re= radius of the earth
me= mass of the earth
therefore it weighs 16 times less
