Se muestran los artículos pertenecientes a Abril de 2019.

## 4ESO FQ English 2018-2019. Unit 4 FLUID STATICS (FORCES). Article 6.

Publicado: 04/04/2019 10:05 por easyfisquim en 4ESO FQ (10th gr Science) 2018-2019

FLUID STATICS

- Website to have a general view and study of this lesson 4 about Fluid statics.

+ What is this lesson about and what does fluid statics study? :

Fluid statics is the branch of fluid mechanics that studies incompressible fluids at rest. It encompasses the study of the conditions under which fluids are at rest in stable equilibrium as opposed to fluid dynamics, the study of fluids in motion.

+ Prelude to Fluid Statics :

What exactly is a fluid? Can we understand fluids with the laws already presented, or will new laws emerge from their study? The physical characteristics of static or stationary fluids and some of the laws that govern their behavior are the topics of this chapter.

* A fluid is a state of matter that yields to sideways or shearing forces. Liquids and gases are both fluids.

+ Fluids vocabulary :                   Fluids dynamics gap text

+  What Is a Fluid?                Go there !!

Liquids and gases are considered to be fluids because they yield to shearing forces, whereas solids resist them. Note that the extent to which fluids yield to shearing forces (and hence flow easily and quickly) depends on a quantity called the viscosity.

+ Density                 Go there !!    Check and copy the definition of density!!

Which weighs more, a ton of feathers or a ton of bricks? This old riddle plays with the
distinction between mass and density. A ton is a ton, of course; but bricks have much
greater density than feathers, and so we are tempted to think of them as heavier.

* Density exercise : CALCULATING THE MASS OF A
RESERVOIR FROM ITS VOLUME.

A reservoir has a surface area of 50km2 and an average depth of 40.0m. What mass of                                 water is held behind the dam?

Problem solved :  FOTO

* Go now to this LINK and produce a table in which to organize several
substances according to their density indicating which ones will float or sink.
Write down their density value and units and beside it say if it will float or
not just comparing them to the water density ( 1 g/ml ).

- Density problems to work out.  Just try them  ( you can check the solutions there).
( Please try to work out the problems by yourself first. If you finally
need help then check the answers given ).

- Pressure is the force per unit perpendicular area over which the force is applied.     In equation form, pressure is defined as :
P = F/A     Pressure equals force divided by surface or area.

F = P.A

The SI unit of pressure is pascal and 1 Pa=1 N/m2.

+ Let’s go to this LINK to learn how important pressure is when considering fluids.

+ ACTIVITY FOR FRIDAY ON THE COMPUTERS :

*Check these two websites  (  WEB1  and  WEB2  ) and make a powerpoint or a word file just organizing and summarizing the different kind of pressures we can find in nature. Make a table or a chart organizing them while explaining their most important features. When you are done (finished) send your work to your teacher's email.

## 4ESO FQ English 2018-2019. Unit 5 WORK AND ENERGY. Article 7.

Publicado: 26/04/2019 06:36 por easyfisquim en 4ESO FQ (10th gr Science) 2018-2019

WORK AND ENERGY

- Website to have a general view and study of this lesson 5 about Work and energy.

+ What is this lesson about and what does work and energy lesson study? :

When a force acts upon an object to cause a displacement of the object, it is said that work was done upon the object. There are three key ingredients to work - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement. There are several good examples of work that can be observed in everyday life - a horse pulling a plow through the field, a father pushing a grocery cart down the aisle of a grocery store, a freshman lifting a backpack full of books upon her shoulder, a weightlifter lifting a barbell above his head, an Olympian launching the shot-put, etc. In each case described here there is a force exerted upon an object to cause that object to be displaced.

In this unit, an entirely different model will be used to analyze the motion of objects. Motion will be approached from the perspective of work and energy. The effect that work has upon the energy of an object (or system of objects) will be investigated; the resulting velocity and/or height of the object can then be predicted from energy information. In order to understand this work-energy approach to the analysis of motion, it is important to first have a solid understanding of a few basic terms. Thus, Lesson 1 of this unit will focus on the definitions and meanings of such terms as work, mechanical energy, potential energy, kinetic energy, and power.

+ Work and energy definition VIDEO                              Go there !!

+ Word definition activity and problems to solve :      Page 1       Page 2       Page 3       Page 4