Answer:The objects in order from least to greatest potential energy:
3<1<4<2
Explanation:
1. Potential energy of a 15-kilogram stone found at a height of 3 meters:

2. Potential energy 10 kilograms of water stored at a height of 9 meters:

3. Potential energy 1-kilogram ball located 20 meters in the air:

4. Potential energy box of books weighing 25 kilograms placed on a shelf 2 meters high:

The objects in order from least to greatest potential energy:
3<1<4<2
In this situation, both of the vehicles turn towards starboard.
By turning to the starboard, or right, side, the vehicles are able to avoid collision. Because waterways are not marked in a manner like roads are, it is necessary to place such conventions of turning in situations where vehicles approach one another head on. If a convention was not in place, the risk of collision would be many times greater. For example, the motorboat operator may turn left, while the PWC operator turns right, resulting in a collision.
Answer:
-2.5 m/s²
Explanation:
The acceleration of a body is the change in it's velocity with time.
The change in velocity with time can be obtained as the slope of a velocity time graph ;
Acceleration = (change in velocity / change in time)
Taking the slope :
Change in Velocity = △y = y2 - y1
Change in time = △x = x2 - x1
(10, 15) ; (0, 40)
△y / △x = y2 - y1 / x2 - x1 = (40 - 15) / (0 - 10)
△y / △x = 25 / - 10 = - 2.5 m/s²