Question

why objects float or sink in the water?

Answer 1

The density of an object determines whether it will float or sink in another substance. An object will float if it is less dense than the liquid it is placed in. An object will sink if it is more dense than the liquid it is placed in.

Answer 2

the density of the object determines that will the object float or sink in water.

object will sink if it has more density
example: a coin will sink into a bowl of water

object will float if it has less density
example: a leaf will float upon the water