February 24, 2014Homework: Finish reading section 2 and

complete cause and effect graphic organizer pg. 79 in NB, Due Wednesday.

Do Now:Write down homework Update T.O.C: pg. 79: Cause & Effect:

Sinking objectsOpen notebook to pg.79- Copy Down Graph. OrgOpen textbook to pg. 82

BuoyancyBuoyancy: The ability to float ex: Ships and boats are designed to have buoyancy

Buoyant ForceBuoyant force : is the upward force exerted

(applied) on an object that is submerged in a fluid.

Water and other fluids exert (give off) this force: Not just in liquids (water) , but also in gases (Air-Hot air balloons)

Acts in the opposite direction of gravity so makes an object feel lighter

Buoyant ForceA fluid exerts pressure on all

surfaces of a submerged object.

Since pressure of a fluid increases with depth—

The upward pressure on the bottom of the object is GREATER then the downward pressure on the top

Results in the net force acting upward on the object: Fig. 7

What happens when the weight of the object is greater then the buoyant force?

It will Sink!

If they are equal? Weight =Buoyant ForceIt will not sinkRemember the weight on an

object is the downward force

Why does the lobster sink?Because the weight of the lobster is greater then

the buoyant force

February 25, 2014Homework: Finish reading section and

complete graphic organizer on pg. 79 in NB.-Finish class work question on pg. 81 (if not

done in class)

DoNOw: Write down H.W, Update T.O.C. pg 80, Buoyant Forces Activity:

pg. 81: Archimedes PrincipleOpen T.B pg. 84Open N.B to pg. 80

Check pg. 80: Are your arrows correct?

Ping Pong Ball--Answer

Marble- Answer

Why did the Bottle sink?

Archimedes Principle (write on pg. 81) The buoyant force (acting on a submerged

object) is equal to the weight of the fluid the object displaces.

The weight of the displaced water is equal to the buoyant force.

Why does a ship have a greater buoyant force then the steel brick?Look at Figure 10- pg. 85

Greater buoyant force acts on larger objects –even if they have the same weight

How does the Ducky & Container Compare to figure 10?

Why does a ship float on the surface?- (in Four sentences or less)The buoyant force equals the weight of the

fluid the object displaces. The buoyant force will increase if more fluid

is displaced. This means that the larger the object, like a

ship, the greater the weight of fluid will be displaced.

This will mean a greater buoyant force which will be able to hold up the ship (making the ship be able to float, not sink…)

What if there is not enough water?