1. Buoyancy is the ability of an object to float.
It is related to the object’s density.
Hardeep Dhillon
M.P.Ed (IV Sem.)
Roll No. 39

2.  Density is the amount of matter (mass) in a
given volume or space
 Gasses are the least dense form of matter
 Liquids are more dense than gasses, but
less dense than solids
 Solids are the most dense form of matter

3.  Reminders:
 Mass = a fundamental measure of the
amount of matter in the object
 Volume = the amount of 3-dimensional space
occupied by an object
 Density = amount of matter contained by a
given volume


4.  The upward force exerted by the liquid on any
object.
 An upward acting force caused by fluid
pressure that keeps object afloat.
 All objects faces the force of buoyancy when
emerged in water.

5. .

6.
B=mg
m = mass of liquid displaced
g = gravitational acceleration

7. Why boats float and
elephants sink
:buoyancy
 How does a boat or ship carrying hundreds of
pounds worth of stuff float while that same stuff
would sink to the bottom of the ocean if dumped
overboard? How come when you're in a pool and
you stretch your body out flat you float. But, if
you wrap your arms around your legs and curl up
into a ball you sink?
 Well, it all has to do with how much water is
pushing against you and a little scientific
principle called buoyancy or floatation. When you
stretch out flat more water pushes against you
since your body is laid out flatter

8. Archimedes' Principle
 A body immersed in a liquid, either wholly or
partially, is buoyed up by a force equal to the
weight of the liquid displaced by the body.

9. Does it sink, or does it float?
1. The body will float if the buoyancy is
positive (body weight smaller than
weight of displaced liquid).
2. The body will be suspended if the
buoyancy is neutral (body weight equals
weight of displaced liquid).
3. The body will sink if the buoyancy is
negative (body weight larger than weight
of displaced liquid).

10. Various levels of buoyancy
depending on weight of the
submerging body
.

11. Apparent Weight .
 When the object is immersed in the
water, the object weighs less due to the
buoyant force.
W′ = W − B
 W′ is the weight of the object in the fluid
 W is the original weight of the object
 B is the buoyant force

12. Thank You
.