TCAP

Luke Williams

Scientific Investigations

1. Identify a testable question. A testable question is one that can be answered by performing an investigation. Questions about opinions and emotions generally do not make good testable questions for experiments, although some information can be gathered about opinions by performing a survey.

Scientific Investigations

2. Research the topic Before an investigation can go any

further, some basic research about the topic must be done. Research can include making observations about things in nature, asking an expert, or looking in books and on the Internet.

Scientific Investigations

3. Form a hypothesis A hypothesis is a possible answer to a

scientific question and is based on gathered information. In science, a hypothesis must be testable. This means that it must be possible to carry out the investigation and to gather evidence that will either support or disprove the hypothesis.

Scientific Investigations

4. Design an experiment to test the hypothesisAn experiment must be designed to test the hypothesis. All factors that can change in an experiment are called variables. The manipulated (independent) variable is the one factor that is changed by the person doing the experiment. The responding (dependent) variable is the result of changing the manipulated variable. A fair test is an experiment or comparison in which only one variable is changed or tested.

Scientific Investigations

5. Collect the data A controlled experiment produces data. Data are things,

such as facts and measurements, that are gathered by making observations during the experiment.

Observations involve the senses of sight, hearing, touch, and smell. Often, scientists use tools, like microscopes, that increase the power of their senses or make their observations more precise.

Data can be recorded by writing or drawing in a notebook. Data can also be recorded by using computers, cameras, videotapes, and other tools. Using tables to record data can help organize observations neatly.

Scientific Investigations

6. Interpret the Data When an experiment is finished, the data

from the experiment should be analyzed. Organizing data in tables, charts, and graphs makes it easier to see patterns and any relationship of one variable to another.

Scientific Investigations

7. Explain Results After gathering and interpreting data,

conclusions should be made about what happened when the manipulated variable was changed.

Scientific Investigations

8. Compare results to the hypothesis The results of the experiment should be

compared to the original hypothesis. Do the results support the hypothesis? Do they disprove the hypothesis? Hypotheses should not be thought of as right or wrong. Something is usually learned from the experiment, even if the results are not what was expected.

Scientific Investigations

9. Communicate the findings The results, analysis, and agreement (or

disagreement) of the findings with the original hypothesis should be communicated to others. Communicating results helps people learn from one another.

Energy Transfer

Energy is the ability to do work. Energy can take several different forms,

including: mechanical energy electrical energy heat energy light energy sound energy chemical energy

Energy Transfer

Mechanical Energy Mechanical energy is the energy that an

object has due to its motion or its position. It can be further classified as kinetic energy, or energy of motion, and potential energy, or stored energy of position.

Mechanical energy is present in: a moving car

a book on a desk a ball that is thrown

Energy Transfer

Energy Transfer

Examples of Energy Transfer Example 1: Jenna has connected a fan, a radio, and a lamp to

an extension cord, which is plugged into the wall. The electrical energy flowing through the extension cord will transfer to which type of energy as it powers the appliances? mechanical energy

sound energy light energy all of these The electrical energy flowing through the extension cord with

transfer to mechanical energy as it powers the fan, sound energy as it powers the radio, and light energy as it powers the lamp.

Energy Transfer

Example 2: Mike is playing the drums. As he beats the drums, the mechanical energy of moving the drumsticks is converted to _______. sound energy

light energy electrical energy heat energy The mechanical energy of beating the drumsticks is

converted into sound energy when Mike plays the drums. When most instruments are played, the musician applies mechanical energy to the instrument, and sound energy results from the instrument, such as in playing the piano, a harp, or a trumpet.

Energy Transfer

Example 3: A plant receives _______ energy and transforms it into chemical energy for food. heat

mechanical light sound A plant receives light energy from the

Sun, and uses that to make chemical energy for food.

Energy Transfer

Kinetic & Potential Energy Kinetic Energy is the energy of motion.

Potential Energy is stored Kinetic energy is defined as energy of motion. When an object is in motion, it has kinetic energy.

The amount of kinetic energy an object has is related to its mass and velocity. The greater the velocity and mass of an object, the more kinetic energy it has.

energy.

Energy Transfer

Energy Transfer

Calculating Kinetic Energy

The kinetic energy of an object can be calculated by using the following equation:

KE = 1/2 × m × v2

where m is the mass of the object and v is the speed of the object.

Calculating Gravitational Potential Energy

Gravitational potential energy can be calculated in ft-lbs by using the following equation: PE = height (ft) × weight (lbs).Gravitational potential energy can also be

calculated in joules (J) using: PE = m × g × hwhere m is the mass of the object, g is the

acceleration of the object due to gravity, and h is the height of the object above the ground.

Conservation of Energy

The Law of Conservation of Energy states that the total amount of energy in a closed system remains constant. Energy can be converted from one form to another, but it cannot be created or destroyed

In physics, there are several conservation laws. "Conservation" means there is no net loss of whatever you are measuring - energy in this case. The input of energy in a physical system is the same as the energy output. EXAMPLE

A gas motor is an example of a system. The gasoline for the motor has a specific amount of potential energy (PE). When the gasoline is burned in the motor, some of that potential energy becomes heat or noise.

As the PE decreases, the kinetic energy (KE) increases. Energy is not lost, it has simply changed forms.

Uneven Heating of the Earth

The Earth's major external source of energy is the Sun. The Earth is constantly receiving solar energy, but different areas of Earth receive different amounts of solar energy. This affects weather and climate.

Different areas of the Earth receive different amounts of sunlight. The equator receives the most sunlight because the Sun is closer to being directly overhead year-round than it is at any other place on the Earth. This increases the amount of heat energy received and explains why areas near the equator have tropical climates. The poles receive the least sunlight, which is why they have cold climates.

The solar energy received by the Earth causes ocean currents, winds, seasons, and climate differences.

Uneven Heating of the Earth

OCEAN CURRENTS—The uneven heating of the Earth's surface creates energy flow. Winds and ocean currents flow from warmer areas to colder areas, which means that they travel from the equator toward the poles.

WIND: LAND BREEZES & SEA BREEZES—In coastal areas during the day, the land heats up more than the ocean. This uneven heating causes wind to blow from the ocean to the land during the day, as the warm air over the land rises, and the cooler ocean air moves in to take its place. These winds are called sea breezes.

In the evening, the land cools faster than the ocean. This causes wind to blow from the land to the ocean, as the warmer ocean air rises and the air over the land moves out to take its place. These winds are called land breezes.

Uneven Heating of the Earth

SEASONS—The Earth's seasons occur because of the tilt of the Earth's axis. When either the Northern Hemisphere or the Southern Hemisphere is tilted towards the Sun, it is receiving the most solar radiation and is experiencing summer. When it is tilted away from the Sun, it is receiving the least amount of radiation and is experiencing winter.

CLIMATE DIFFERENCES: COASTAL VS. INLAND—Oceans also have a major effect on climate. Water absorbs solar energy without changing temperature much. This means that ocean temperature remains within a small range throughout the year, even when the amount of solar energy received is changing. This explains why the climate in coastal areas changes less with the seasons than areas that are far away from the coast.

Movement of Ocean Water

There are three major types of water movement in the ocean. They are:

1. Currents – continuous, directed movements of ocean water that are produced by forces acting upon the water. Surface ocean currents are primarily formed by winds that cause the water to move in the direction that the wind is blowing. Deep ocean currents form due to Earth's gravity—different sections of ocean water sink and rise as currents due to differences in density. These density differences are caused by differences in salinity and temperature.2. Tides – rising and falling of the water level caused by the gravitational forces of the moon and the sun3. Waves - vertical movements of water, typically involving waves moving towards the shore and breaking in shallow water near the coastline

Atmospheric Convection & Wind

Atmospheric Convection & Wind

Atmospheric Convection

The Sun is the ultimate driving force for weather and climate patterns on Earth. Due to Earth's shape, position, and movement through space, the Sun heats Earth's atmosphere unevenly. Only half of Earth receives sunlight at one time. In addition, solar rays are more concentrated at the equator than at areas of higher latitude. Thus, some parts of the atmosphere become warmer than other parts.

When air heats up, it becomes less dense and rises. Colder, denser air sinks and moves in to take the place of the rising, warmer air. This constant circulation of air is driven by temperature differences, and is called convection.

Atmospheric Convection & Wind

Wind

Warm air has a lower pressure than cool air. Warm air molecules are spread out; therefore, they do not place a lot of pressure on the area beneath. Cool air molecules gathered close together place greater pressure on the area beneath.

To maintain a balance, air masses flow from areas of high pressure to areas of low pressure. It is during this process that wind is produced.

The uneven heating of the Earth is the cause of weather differences like low- and high-pressure zones, strong and light winds, temperature differences, stormy and fair weather, humid and dry conditions, and stable and unstable air conditions. Low pressure areas tend to have stormy weather and stronger winds. High pressure areas tend to have fair weather and light winds.