Relative motion in water refers to the movement of an object in relation to a body of water. It takes into account the object's own motion as well as the motion of the water it is moving through.
The density of water greatly affects relative motion. Objects with a higher density than water will sink, while objects with a lower density will float. This can also impact the speed and direction of an object's motion in water.
The shape of an object can greatly impact its relative motion in water. Objects with a more streamlined shape will experience less resistance and will be able to move through water more easily compared to objects with a larger surface area.
The main difference between relative motion in water and air is the density and viscosity of the medium. Water is denser and more viscous than air, so objects will experience more resistance and slower motion in water compared to air.
The speed of an object can greatly impact its relative motion in water. As an object moves faster, it will experience more drag and resistance from the water, making it more difficult to maintain its speed. However, the shape and density of the object can also play a role in its ability to maintain speed in water.