Page 99 - Primary Five Science

Floating

This is when an object put in a liq-

uid stays on top of or remains

partially submerged. Ob-

jects float on liquids if they
are less dense than those

liquids

E.g. Objects float on water

because their density is

less than the density of wa-

ter.

Examples of things which float on
water include cork, wood, plastic, rubber,

feathers, a leaf, papers, paraffin, petrol etc.

.Sinking
This is when an object put in water goes to the bottom of the

water. Objects sink because their density is greater than the

density of the water or liquid in which they sink.

Examples of objects or substances that sink are; stones, sand,

soil, metal, glass, nails, sugar, salt, mercury, etc.

NB: A sinking object displaces water equal to its volume

while a floating object displaces water equal to its weight.

Up thrust force or Buoyancy

Up thrust is the force that liquids exert on to objects put in

them. Up thrust make objects weigh less when immersed in

liquids.

Ships float on water basing on this principal.