The normal force would be the opposing and equal force to gravity ... that is why the box isn't floating or going through the ground ... this is Newton's third law of motion
The body releases endorphins
The RATE of change of position is speed.
There will not be enough momentum from the first hill to cross another hill if he same or larger size because of the way potential energy and kinetic energy works it will not be able go as high as it could go on he fist hill.
Where are the images?!?!?
