This should help look at the pictures?
Distance covered is given as follows
1). 7 km North
2). 5 km North
3). 1 km East
Now total distance covered will be given as
Now in order to find the displacement we will show all with their directions
towards North
towards East
So total displacement is
so net displacement will be
so displacement is 12.04 km
It results change only in it's kinetic energy, it's KE will increase in accord with the work-energy theorem
Yes. Acceleration means any change in speed or direction of motion. When an object coasts in a circular orbit at constant speed around the Earth, its direction is constantly changing. The acceleration is "CENTRIPETAL", which points toward the center of the circle.