Our Fun Experiment !

Our Fun Experiment !

In our experiment we are observing about how do cells grow. Our experiment is to observe how do the yeast grow with sugar and with only yeast and hot water. The thing that we need to do this experiment are  :

•  2 sachet Yeast
• 3 + table spoon of sugar
• Hot Water
• 2  Conical Flasks
• Plastic Spoon
• 2 Balloons

After we already have all of the equipments, then you can do the experiment. The steps to do this experiment are :

1. Label the conical flask 'A' and 'B'.
2. Pour 30 ml of hot water to each of the conical flask.
3. Add a flat spoon of yeast to flask A and close the flask right away with a balloon.
4. Add a flat spoon of yeast to flask B and a flat teaspoon of sugar and close it right away with the balloon.

Then we used a stopwatch to record the time and we used a measuring tape to measure the distance around the balloon.

This is our record of our experiment.

Flask A :
0 min : 0 cm
15 min : 11 cm
30 min : 13 cm
45 min : 12 cm

Flask B :
0 min : 0 cm
15 min :22 cm
30 min :30 cm
45 min :32 cm

When we are doing this experiment, we were really panic about the ballon in the flask B. It was so big and we thought that it's gonna explode. So we asked our teacher if it's really gonna explode. But she said it will not explode. It was actually like that. So we wait. But in the middle of the experiment our stopwatch is accidentely been reset. But we found the way to solve this problem. It's a good thing that we remember what minutes did we stop on. We did really well in this experiment.

In this experiment I conclude that in order of the cells to grow and multiply,they need an enough energy. In this experiment the yeast is playing a roll of the cell and the water and sugar is the source of energy.

Here are the pictures of the yeast experiment :

There are some articles that I read about this experiment and I hope you can read it also because it is a really good article :

• http://www.sciencebob.com/experiments/yeast.php
• http://www.experiment-resources.com/magic-balloon-experiment.html
• http://www.education.com/activity/article/Yeast_Balloons/

Our Talkshow

Our Talkshow

This talkshow is one of our AA (alternative assessment) for Science. We were grouped in 5. My member in this group was :

• Theo
• Marsha
• Ivia
• Jerry
• Eugenia (me)

We were playing a differeent tasks in our group. Here are the tasks taht the group leader had choosen for us :

• Theo : PPT Maker
• Ivia : Researcher
• Jerry : Researcher
• Marsha : Host
• Eugenia : Guest Star

The topic that we picked was about the alcohol. In how they can affect our body ? What drinks that contains alcohol ? And something else. At the day before we did this talkshow I was absent. So the second day I was rushing to memorize my lines. But I did really well because we did not really refer to the topic but we just use our own words and we used our knowledge to answer this questions. The hardest part that I experienced in this talkshow is when the audience asked us about the topic of the talkshow. But it's the good thing that I could answer it really well.

Here are some pictures of our talkshow :

This the pictue of me doing the talkshow with my friend Marsha.

This another picture of our talkshow.

This is the pictue of the other groups.

This is another picture of the other groups.

This is another picture of the other groups.

Those are the pictures of the Talkshow. 

These are some sights about alcohol that I had read about :

• http://kidshealth.org/teen/drug_alcohol/alcohol/alcohol.html#
• http://ezinearticles.com/?How-Does-Alcohol-Abuse-Kill-People?&id=1980931
• http://www.hazelden.org/web/public/ade90201.page



My Sound Experiment

Hi there ! Today I am going to tell you about my experiment about sound. The experiment is making the telephone. We were working in pairs. First we were asked to make a hole at the bottom of the plastic cup. Then, we put the strings between them. Then we pant the plastic cup and tried the experiment. Finally we therefore conclude that sound will travel faster through string than through the air.

Here are some pictures of the experiment :

Let's Find Out about Sound !!!

Let's Find Out about Sound !!!!!!!!!

What is sound ?

Sound is an amount of vibration that enters our ears. 

How does sound travels ? 

Sound travels in all directions. When an object produces sound, the sound travels away from the object in all directions. Sound can travel through water and air. 

What is sound wave ? 

Sound wave is the squezing and strechting of sound.

How do we hear sound , and how might it affect hearing ?

Sound waves travel to the air and enters the ear drum and allows it to vibrate.
To much loudness might affect our hearing or can cause us deafness.

How do sound transfer to the inner drums ?

The incoming sound waves that are sent to the eardrum cause it to vibrate. These vibrations in turn cause movement in three small bones called ossides, that are connected to the inner ear.

Sound travels away from the source

When we drop a small pebble into a pond, we can see ripples on the surface of the water. These ripples travel away from the pebble in all directions.

When an object produces a sound, the sound travels away from the object in all directions. Object that produced sound is called source of the sound.

The loudness of the sound decreases as the sound travels farther away from the source. When we are very close to the source of the sound, it becames loud. When we move away from the source of the sound, the sound becames softer.

Sound requires a medium to travel 

Sound requires medium to travel. When an alarm clock rings, we can hear the sound because the sounds travels through the air reaches our ears. In this case, air is the medium through which sound travels.

A space has no matter in it is called a vacumm. Vacumm can be created in an empty jar by sucking out all the air from it. We cannot hear an alarm clock when it rings inside a jar with a vacumm because there is no air or any other medium through which the sound travels. 

 

Sound can travel through solid, liquid or gaseous material. Travels at different speeds in different media.

Sound travels in all directions. Sound travels faster through most solids and liquids than in the air. It is why we can hear the other person talking into the tin can at the other end of the tin can telephone. Sound travels faster through a string than through the air.

 

What is Light and Heat ?

What is Light and Heat ?

What is refraction ?

Light travels in straight lines. However, when it travels from one medium to another, for examples, from air to water, it bends. Bending of light at the boundary of the two media is known as refraction. It occurs because the speed of light changes as it enters a different medium.

How does a lens work ?

A lens is a carefully moulded piece of transparent material, such as glass or plastic, which refracts light to form an image.

When we look through a lens, we observed that the image of an object gets distorted. It's because light undergoes refraction as it travels from air to glass, and back to air again.

Lenses are usually used to magnify or reduce the size of the images of object. they are used :

Magnifying glasses

microscopes

spectacles

cameras

telescopes

Dispersion of light through a prism

We can prove this by shining white light through a prism. A prism is a transparent plastic or glass object, with smooth flat sides, that can refract light.

White light is refracted twice as it passes through a prism once, when it travels from air to the prism, and a second time when it travels from the prism to air. Light that comes out of the prism is no longer white, but it is broken up into the colours of rainbow. The breaking up of white light into its component colours is known as dispersion.

Dispersion occurs because of light of different colours travel at different speeds. Red light travels the fastest so, it refracts the least. Violet light travels the slowest so, it refracts the most. That is why red is always seen at one end of the rainbow, and violet at the other end.

Dispersion of light through water droplets

Water droplets in the air can act as tiny prisms. The droplets can be from the rain, the mist of a waterfall or a fine spray of water from a garden hose. It refract the sunlight the same way a prism does, and produce rainbows.

Transfer of heat

As light travels from one medium to another, heat also travels from one object or place to another. Heat travels from a region of higher temperatures to a region of lower temperature through conduction, convection and radiation.

Conduction

Heat can transfer transfer from one part to another within an object between objects.

An object is heated up, its particles collide with one another. Heat is transferred from the hotter region to the cooler region through these collisions of particles.

Conduction also occur between objects. Heat transferred when particles of both objects are touching each other.

Convection

Transfer of heat from one region to another by the movement of fluids is know as convection. 

A fluid is heated up, it expands. This means that its volume increases an its density decreases.

Hotter less dense fluid then rises and floats. Cooler, denser fluid flows to take its place. 

Radiation

Radiation release heat from the surface of most bodies that transferred  directly from one region to another.

Heat directly transferred without having to travel through any substance. Means that heat can be transferred without air.

.

Let's Find out about Materials and their Properties !

Relationship between the properties of materials and their uses

Objects around us are made of different materials. We choose materials to make objects based on their properties of the materials that we were using.The objects that are made of the right materials will be very useful. Some useful properties of materials are the degree of transparency to light, magnetic property, heat conductivity and electrical conductivity.


Let us look at how the materials with these properties are used for making objects.








Uses of materials based on their heat conductivity

Materials that are good conductors of heat are used to make object that allow heat to pass through them quickly. Materials that are poor conductors of heat are used to make object that prevent heat from passing through them. Poor conductors of heat are also called insulators of heat. 

Steel , iron and other metals are used to make the body of pots and other cooking utensils to cook food quickly.

Uses of materials based on their degree of transparency to light

Materials which are transparent to light allow most light to pass through them. Transparent materials are used to make objects that can see through, such as windows. Materials that are opaque do not allow light to pass through them. Opaque materials are used to make objects such as doors and walls. Doors and walls of buildings need to be opaque to protect our own privacy.

Uses of materials based on their electrical conductivity


Materials that allow electricity to flow through them are used to make objects that conduct electricity. Materials that do not conduct electricity are used to make objects that prevent electricity from flowing through them. Two or more types of materials may be found in the same object. They are used to make different parts of the object. 

 

 Uses of materials based on their magnetic property
Magnetic materials and magnet work together to hold objects together.





Not all materials have properties which are suitable for making object. Do, when we are choosing materials to make an object, we need to know the :

• Properties of the materials.
• Use of the object. 

Let us look at some examples of common materials, their properties and their uses.

Sink

A sink must not absorb water. It must keep a fixed shape. The material we use to make sink must be :

• Waterproof.
• Strong.
• Hard.

As ceramic has these properties, it is used to make the sink.

Drinking bottle

A drinking bottle must not absorb water or break easily. It must be easy to carry around. The materials we used to make the drinking bottle must be :

• Hard
• Waterproof
• Light

As plastic has these properties, it is used to make the drinking bottle.

Bench

A bench must be able to support heavy weights and not bend. The materials we use to make the bench must be :

• strong
• rigid

As metal has these properties, it is used to make the bench.

Windows

Floor-to-ceiling windows must stay upright, keep a fixed shape and allow most light to pass through it. The material we use to make floor-to-ceiling windows must be :

• hard
• rigid
• transparent

As a glass has these properties, it is used to make floor-to-ceiling windows.

Treadmill belt

The walking belt of a treadmill must be bend easily and cushion the steps of a person. The material we use to make the walking belt must be :

• flexible 
• soft

As rubber has these properties, it is used to make the walking belt of the treadmill.

Materials are also used to make household items such as bleach, pesticide and medicine. Although these items are useful, they may also be poisonous. So, to keep everyone safe from harm, we need to handle them correctly. We can do this by :

• labelling them properly
• using them for their intended purpose
• keeping them in suitable places
• disposing used materials properly

Labelling household items properly 

 To keep everyone safe, it is very important to label hazardous, and essential household items properly. 

Sometimes, we may see the international warning signs for chemicals on certain household items. These warning signs let us know the dangers of the chemicals.  For example, aerosols are flammable and are usually labelled with  the warning sign for flammable materials.

Using household items for their intended purpose

Should follow the instruction on the label of a household item. Using the household item only for its intended purpose. Using the correct quantity of the household item. Using a household item in the wrong quantity or for the wrong purpose can be dangerous. Chemicals in the household item may react with other chemical to produce poisonous products. We need to ensure we do not mix or use materials for purposes other than what they are meant for.

Taking medicine, we should follow the instruction on the label, because taking more medicine than what is necessary may cause poisoning.

The label also tell us what the medicine is for. Taking the wrong medicine for our illnesses can worsen our condition. We should not share our  medicine with others or take another person's medicine.

 

Keeping household items in suitable places

Always follow the storage instruction on the label found on household items.Proper storage of household items ensure that the chemical in the household item do not  mix and  cause poisonous substances to form.
Household item should be kept away from food to avoid contamination of food.Should not keep household item in container that look like food container.
We should keep household item containing corrosive and flammable chemicals in separating places. If these household items are stored together they might mix and react to form poisonous gases or cause fires.
Should store flammable and volatile chemicals in cool areas away from sunlight and other sources of heat such as stoves.
Should store corrosive chemicals away from metallic objects as they can cause metals to corrode.

Disposing of used materials 

Household items are no longer useful to us, they become waste or used materials, which we also need to dispose of properly. We produce different types of waste. Types of wastes include recyclable waste, non-recyclable waste and chemical waste.
Let us look at how we should dispose each type of waste.

Disposal of recyclable materials

Recyclable materials such as paper, metals and plastic should be dispose in recycling bins. We should not throw non-recyclable materials into recycling bins.

Disposal of chemical waste

Old paint, old aerosol sprays, expired medicine and household cleaning liquids contain unwanted chemicals or chemical waste. Chemical waste is harmful to our health and can pollute our water supply. May even cause explosions if it mixed with other chemicals.


Here are some ways we can dispose of chemical waste safely.


Make sure that aerosol spray cans are completely empty by pressing the button top of the cans before throwing them away. This releases any gas left in the cans.


We should make sure that leftover paint is completely dry before disposing it.


Wear gloves when disposing household cleaning liquids such as bleach or window cleaners. These liquids contain chemicals which irritate our skin. 


We should return expired medicine to local pharmacy for proper disposal. Should not flush it down the drain.

Let's Find Out About the Weather !!!

Different types of clouds are formed at different heights in the atmosphere.

The 3 main clouds are : 

• Cumulus clouds
• Stratus clouds
• Cirrus clouds

Cumulonimbus

This clouds is a cumulonimbus clouds. Cumulonimbus clouds extend from a height 2000 m to 16 000 m in the atmosphere. When cumulus clouds turn into dark grey , they are called cumulonimbus which can produce rain, hail or lightning.

Cirrus
Cirrus clouds are formed very high in the atmosphere at 8000 m. These clouds are wispy and light, and look like feathers in the sky.

 Nimbostratus
Nimbostratus clouds are formed below a height of 2400 m in the atmosphere. They bring long steady rain and a resemble grey blankets strecthed out in the sky.

 Cumulus 

Cumulus clouds are formed at about a height of 2000 m in the atmosphere. Cumulus clouds are white and fluffy like cotton balls.

Stratus 

Stratus clouds are formed below a height 2000 m in the atmosphere. Stratus clouds are flattened sheets of clouds that may stay over certain location for some time. They cause overcast weather.

Fog

A fog is just like a low-lying cloud. It hovers just above the ground because it is formed when the ground is cold, such as winter or at night. The water vapour in the air condenses into tiny droplets of water to form fog.

Dew

Dew appears as drops of water on cold objects usually in the early morning or late evening. Dew is formed when water vapour in the air comes in contact with a cold object of a temperature at or below the dew point. The temperature at which droplets can form is called the dew point.

The water vapour then condenses to form small droplets on the cold surface.

Hail

Hail is a form of precipitation that falls from sky as clumps of ice. Precipitation is produced when water vapour from the sky condenses and falls to the ground.

 Formation of hail 

1. During thunderstorms, there are updrafts or upward currents of air, caused by the rising warm air.
2. The updrafts may be strong enough to carry raindrops into the upper levels of the atmosphere.
3. The upper levels are extremely cold so the raindrops freeze as ice crystals.
4. As the ice crystals become larger and heavier, they can no longer be supported by updrafts.
5. They then fall to the ground as hail stones.

Wind

The movement of air causes wind.

Formation of wind

1. When the surface of earth is heated up by the Sun, the air above it is also heated up.
2. The warm air expands and rises into the upper atmosphere. This creates a region of low pressure, where there is less air. 
3. In another region, where the surface of Earth is cooler air above it is also cooler.
4. Thus, cooler air from this region of higher pressure rushes in to replace the warm air.

Effects of wind on living things and the environment

Wind affects the activities of man, animals, plants and the environment. Man, other animals and plants may use wind for their benefit but sometimes, wind may have a negative effect on the environment.

Man

Man relies on wind for some recreational activities such as windsurfing and kite-flying. We rely on wind to generate electricity in wind power stations. However, strong winds may damage properties and affect aviation.

Animals

Some animals make use  of the wind to smell their prey. The smell of their predators in the wind also helps warn some animals of any dangers.

Plants

Some plants need the wind to disperse their seeds. However, strong winds may uproot trees.

Environment

Wind causes rocks to erode. Strong winds that carry heavy rain, such as tornadoes and hurricanes, can cause floods.

Sea breeze and land breeze

Wind is also formed when land and water are heated.

Heating of land and water causes the formation of sea breeze during the day and land breeze during day and night.

Heating of land and water

Some surfaces take a longer time to heat up and to lose heat than others. Water takes longer time to absorb heat up to compared to land. It also takes a longer time to lose the heat and the cool down compared to land.

Formation of sea breeze

During the day, the Sun heats up the sea and land. The movement of air from the sea to the land causes sea breeze during the day time.

1. The land absorbs the heat from the Sun and warms up faster than the seas.
2. The air aboves the land is heated up and rises.
3. Cooler air above the sea moves in to replace the warm air above the land.

Formation of land breeze

At night, there is no heat from the Sun. Both the sea and the land begin to lose heat. The movement of air from the land to the sea causes land breeze at night.

1. The land loses the heat faster than the sea, and cools down faster.
2. The air above the sea is now warmer and rises.
3.   Cooler air above the land moves in to replace the warm air above the sea.