YOU´VE GOT THE POWER

WHY WE SHOULD KEEP ELECTRICITY?

                                              “YOU´VE GOT THE POWER”

A world without electricity would be uncomfortable or even hard for nowadays humans. Electricity is a form of energy, and without energy, nothing will exist, because it is everywhere. Fortunately, humans are so creative, because they can create electricity; also, it is easy to do! But at the same time, we don’t understand that if we don´t take care of it, it will get over and affect the humans and their vital daily necessities.

Everything is useful to create electricity, even natural resources, renewable and non-renewable. However, humans and their bad use of it are getting electricity over. That is why we should conserve electricity by not wasting it. Also, there are common and easy ways to reduce the use in our common life, for example, turning unnecessary lights off, taking shorter baths, not opening so much the refrigerator, and many more easy and simple ways to save energy that is one of the most important things for humans.

In conclusion, it´s time to react and change our bad use of energy and unnecessary waste of this essential resource, because at final, we´ve got the power.

REFERENCE:

http://energyquest.ca.gov/movieroom/index.html

ANALYZING ACCELERATION EXPERIMENT

Analyzing and studying the acceleration, speed and velocity of a marble as a Go-cart in different contexts such as changes in velocity and direction.

Hypothesis: When a marble advance through several points, its velocity decrease, and when a marble changes direction by hitting another object, it decelerates.

Objectives.

__Analyze acceleration in different contexts, such as velocity and direction.

__See if an object accelerates or not if hits something.

__Know how to apply the theory of acceleration in the daily life.

__Learn how acceleration can affect effective and quality of an object.

Materials and Reactives.

- Marble

- Chronometer (Timer)

- A channel or tunnel-like surface.

- Measuring Tape.

- Paper and pen. (To take notes and mark distances)

Procedure.

Measure with measuring tape a distance (optional) in the channel-surface.

Mark the limits and distances.

Throw the marble and start recording the time to see its velocity

Now, mark some distances and get the time when the marble reach it to see its acceleration or deceleration.

Record these results and make some calculations.

Now repeat these steps throwing the marble faster or slower.

Now, in a wall (it has to be in the floor) throw the marble (no in right angle) to see a change in direction.

Take the time it takes the marble to reach the wall and a certain point, to see if it accelerates or decelerates.

Record these observations and make some calculations.

Observations and Results.

In every time we throw a marble in any distance, as it progresses it lose velocity and goes slower.

When a marble hits another object and changes direction, it goes slower or even stops.

If you throw the marble with more impulse it will go faster and last farther or even over pass the solid limit. (Vice versa)

Between more distance there is, less velocity the marble will have as it progresses. (Vice versa)
 

Conclusions

The impulse and distance affects velocity and acceleration of an object.

NEWTON´S LAWS OF MOTION

1^st Law (Law of Inertia) – “An object at rest will stay at rest, and an object in motion will stay in motion at constant velocity, unless acted upon by an unbalanced force” “An object at rest will stay at rest, and an object in motion will stay in motion at constant velocity, unless acted upon by an unbalanced force”

“Inertia is the tendency of an object to resist changes in its velocity: whether in motion or motionless”

Example: “Once airborne, unless acted on by an unbalanced force (gravity and air – fluid friction), it would never stop! Unless acted upon by an unbalanced force, this golf ball would sit on the tee forever”.

2^nd Law – Force equals mass times acceleration: “The net force of an object is equal to the product of its mass and acceleration, or F=ma”    “When mass is in kilograms and acceleration is in m/s/s, the unit of force is in newtons (N)”

 “One newton is equal to the force required to accelerate one kilogram of mass at one meter/second/second”

Example: How much force is needed to accelerate a 1400 kilogram car 2 meters per second/per second?

1. Write the formula

2. F = m x a

3. Fill in given numbers and units

4. F = 1400 kg x 2 meters per second/second

5. Solve for the unknown

6. 2800 kg-meters/second/second = 2800 N.

3^rd Law – For every action there is an equal and opposite reaction. “According to Newton, whenever objects A and B interact with each other, they exert forces upon each other. When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body”

There are two forces resulting from this interaction - a force on the chair and a force on your body. These two forces are called action and reaction forces.

Example: “Consider the propulsion of a fish through the water. A fish uses its fins to push water backwards.  In turn, the water reacts by pushing the fish forwards, propelling the fish through the water”

EXPLORING THE WORLD OF PHYSICS

Go to this page, create an account if you want, and start exploring and getting introduced to the world of physical science:

http://my.hrw.com/tabnav/controller.jsp?isbn=0030462495

ANALYZING VELOCITY AND CHANGES IN MOTION OF TWO MODELS OF SPEEDBOATS IN DIFFERENT CONTEXTS TO SEE WHICH ONE IS BETTER

Colegio Gimnasio Vermont Medellín

STAGE 1

STAGE 2

Science

Seven A (7A)

By

Sebastián Vergara

Medellín, Antioquia

April, 2013

ANALYZING VELOCITY AND CHANGES IN MOTION OF TWO MODELS OF SPEEDBOATS IN DIFFERENT CONTEXTS TO SEE WHICH ONE IS BETTER

Introduction….

Theoretical Background

Click the link to follow the activities step by step: http://my.hrw.com/sh2/sh07_10/student/flash/virtual_investigations/hst/mot/hst_mot_vi.html

Motion:

Everything surrounding us is moving. To detect the motion you need a Reference Point (something that appears to be quiet). When an object changes position over time relative to a reference point, the object is in motion and you can describe the direction of the object´s motion with a reference direction such as north, south, etc.

Speed:

Any time that you move, you get a distance traveled in relation to the time, that is called speed, but if you don´t move, speed is happening and it is equal to 0.

Most of the time, objects do not travel at a constant speed.

Speed could be calculated following the equation:

<!--[if !msEquation]--> <!--[endif]-->Velocity:

Is the speed of an object in a particular direction. The terms speed and velocity do not have the same meaning. Velocity must include a reference direction.

Acceleration:

Acceleration is the rate at which velocity changes. Velocity changes if speed changes, if direction changes, or if both change. So, an object accelerates if its speed, its direction, or both change.

An increase in velocity is commonly called positive acceleration. A decrease in velocity is commonly called negative acceleration, or deceleration.

You can find average acceleration by using the equation:

<!--[if !supportLists]-->1.      <!--[endif]-->Objectives

STAGE 1:

<!--[if !supportLists]-->a)      <!--[endif]-->Analyze a new design for a speedboat.

<!--[if !supportLists]-->b)      <!--[endif]-->Evaluate the speedboat design.

<!--[if !supportLists]-->c)      <!--[endif]-->Make some calculations evaluating the speed and acceleration from the speedboats.

STAGE 2:                                                                                                                                  a)   a) Analyze the acceleration of the speedboats in both currents of a river (upstream and downstream)                                                                                                                                              b)   Identify the data of the boats to fill the chart.                                                                        c)   Decide which boat is better based on all these information and the fuel consumption.

Materials and Reactives

VIRTUAL (BOTH STAGES) 2 models of boats, one old and the other one new. Timer Calculator Fuel PHYSICAL (BOTH STAGES) Computer Paper and Pen to take notes (optional)

Procedure

STAGE 1:

Move the speedboats from Point A to Point B.

Calculate the average acceleration between one point and other.

Record your answer filling the data chart.

Decide which model has the higher average acceleration.

STAGE 2:
 

Click Start to begin the race in downstream.

Click on Gear 2 approaching Point A to change speed.

Click on Gear 3 approaching Point B to change speed.

Fill the chart with your data and calculations.

Repeat the steps 1-4 with upstream direction.

<!--[if !supportLists]-->4.      <!--[endif]-->Observations and Results

TRY YOU THE EXPERIMENT!: http://my.hrw.com/sh2/sh07_10/student/flash/virtual_investigations/hst/mot/hst_mot_vi.html

<!--[if !supportLists]-->5.      <!--[endif]-->Conclusions

<!--[if !supportLists]-->1.      <!--[endif]-->  The more speed you have, the more acceleration will result, the less time you have, the less acceleration will result.

<!--[if !supportLists]-->2.      <!--[endif]-->The new speedboat has the more acceleration.

<!--[if !supportLists]-->3.      <!--[endif]-->A speedboat goes faster downstream.                  

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

SCIENCE FAIR

Our Science fair for this year was about how can a plant could grow better, with artificial light or with sunlight?
Our hypothesis is that the plant could grow better, taller and leafy with the light of the sun, because it provides the plant more nutrients and vitamins that permint a better development of the process of the photosynthesis. 

Follow the link below to see all the information about the topic, procedure, observatiosns, conclusions, etc:
file:///F:/MATERIAS/SEPTIMO/BIOLOGIA/SCIENCE%20FAIR%20PLANTS%20GROWTH.htm

Sebastian Vergara y Alejandro Castaño