Lain-lain Mhs dalami lagi ide-idenya Perlu bantuan mhs utk membuat daftar .

Measurement systems (based upon standardized units) English system: Some units based upon parts of the human body: Pond (lb) 1 lb = 454 g or kg Inch, Feet, Yard, Mile Second Fahrenheit, Celcius Metric (SI) system Established in base units: kilogram (kg) meter (m) second (s) kelvin (K) mole (mol) candela (cd) ampere (A) All other units derive from these

How a unit is standardized? Length 1 m = distance light travels in 1/299,792,458s Time 1 s = 9,192,631,770 periods of Cesium 133 Oscillation FOCS 1, (Fountain of Caesium) an atomic clock in Switzerland, started operating in 2004 at an uncertainty of one second in 30 million years Previous standard: 1 s = a fraction 1/(86400) of a day 1 s = a fraction of a year Tangkai sepanjang 0,994 m menghasilkan periode 2 detik.

The density ratio Mass Referenced to standard metal cylinder or boxes

The Scientific Method 1. Observation 2. Hypothesis / Prediction 3. Experiments 4. Conclusion or modification as required 5. Return to 3.

Hypothesis / Prediction - Examples 1. Atoms are made of electrons orbiting nuclei made of protons and neutrons 2. Negative electrons orbiting positive nuclei 3. Colliding two atoms will produce free electrons and nuclei

Experiments Controlled experiment - comparing two situations with all factors alike except one Then conclude if the different factor bring effect to the result.

Laws, Models and Theories Setelah adanya observation, hypothesis dan experiments akan muncul: Laws Sebuah sifat yang jelas teramati dari benda atau alam. Misalnya: Charles’s Law – hubungan antara temperatur dan tekanan gas Theories Kumpulan dari beberapa hasil (bukti) dari experimen, dijabarkan dengan gambar dan deskripsi. Models Penggambaran dari sebuah hypoyhesis atau teori, bisa dengan gambar atau dengan persamaan matematika Berguna untuk menggambarkan benda yang terlalu kecil atau terlalu besar

Example: Model of a rainbow A beautiful double rainbow! The result of the reflection and refraction of sunlight within individual raindrops

Pertemuan ke-2 Energy: 1.What is Energy? 2.Forms of Energy 3.Energy Conversion 4.Law of Energy Conservation

Energy: 1.What is Energy? 2.Forms of Energy 3.Energy Conversion 4.Law of Energy Conservation

What is Energy? Energi adalah sesuatu yang dibutuhkan oleh seseorang atau sebuah benda atau alat untuk melakukan kerja. Yang dimaksudkan dengan melakukan kerja antara lain adalah melakukan gerakan, menahan gerakan dan memanaskan temperatur suatu benda. W = m.a.s W = m.C.  T

What is Energy? Units for Energy: Joule, calorie, Calorie 1 Joule = 0.24 cal, or 1 cal = 4,17 Joule 1 Cal = 1000 cal = kcal =4170 Joules 1 g of carbohydrate produces 4 cal 1 g of protein produces 4 cal 1 g fat produces 9 cal 1 g alcohol produces 7 cal

Energy: 1.What is Energy? 2.Forms of Energy 3.Energy Conversion 4.Law of Energy Conservation

Forms of Energy Energi Nuklir (Nuclear Energy) Termasuk energi nuklir fusi di matahari Energi Pancaran (Radiant Energy) Gelombang Elektromagnetik termasuk sinar matahari Energi Kimia (Chemical Energy) Energi yang terkandung di dalam makanan dan zat-zat lain Energi Mekanik (Mechanical Energy) Energi yang menggerakkan alat-alat mekanik Energi Kinetik (Kinetic Energy) Energi yang menghasilkan gerakan otot atau benda lain Energi Potensial Gravitasi (Gravitational Potential Energy) Energi yang terkandung pada benda yang memiliki ketinggian Energi Potensial Pegas (Elastic Potential Energy) Energi yang dimiliki oleh benda pegas Energi Listrik (Electrical Energy) Energi yang dimiliki oleh arus listrik Energi Panas (Heat) Dll

Energy: 1.What is Energy? 2.Forms of Energy 3.Energy Conversion 4.Law of Energy Conservation

Energy Conversions

Energi Radian Cahaya Energi Kimia Energi Panas Energi Mekanik Energi Listrik

Energy Conversions Within the mobile phone electrical energy converts to lights and sound. Within the audio set electrical energy converts to sound.

Energy: 1.What is Energy? 2.Forms of Energy 3.Energy Conversion 4.Law of Energy Conservation

Law of Energy Conservation Energy is never created or destroyed Energy can be converted from one form to another but the total energy remains constant Exception: Rare case of energy – mass conversion according to Einstein’s E = MC^2

Energy Sources Today Wood, Coal, Petroleum 89% can be traced to photosynthesis Uses 1/3 for heating 2/3 in engines and generators

Modern Solar Technologies Solar Cells Polycrystalline compounds that generate electricity when exposed to light Power Tower Steam produced by focused sunlight generates electricity Wind Energy Sunlight differentially heats earth’s surface creating winds. Wind then generates electricity Agriculture and Industrial Heating Utilizes sunlight rather than traditional energy sources Biomass Utilizes material formed by photosynthesis Ocean Thermal Energy Conversion (OTEC) Generates electricity form the temperature difference between water depths

Geothermal Energy Energy from beneath the earth’s surface Dry steam Hot water Hot dry rocks Difficult to utilize this energy economically

Hydrogen Used directly in fuel cell or burned to release heat Produces no pollutants Only emission is water Problem is that hydrogen does not exist on or under earth’s surface in usable amounts Must be obtained from chemical reaction

Hydrogen Hidrogen dapat digunakan langsung untuk pembakaran. Hidrogen bersama oksigen bisa membentuk fungsi sel baterai. Problem: Unsur Hidrogen tidak tersedia dalam jumlah cukup kecuali dalam bentuk senyawa air. Untuk membuat Hidrogen dari air melalui proses elektrolisis dibutuhkan energi listrik, bisa berasal dari baterai atau solar cell.

Hydrogen Hidrogen yang dibuat untuk ditampung / disalurkan menuju ke ruang pembakaran, misalnya untuk bahan bakar mobil. Melalui proses elektrolisis yang membutuhkan energi listrik, bisa berasal dari baterai.

Hydrogen Hidrogen yang dibuat untuk ditampung kemudian dimanfaatkan sebagai baterai (Fuel Cell). Melalui proses elektrolisis yang membutuhkan energi listrik, misalnya dialirkan dari solar cell.

References 1.Robert Resnick, David Halliday,Kenneth S. Krane, “Physics (Volume 1)”, Fifth Edition, John Wiley & Sons, New York, Douglas G. Giancoli, “Physics for Scientists & Engineers with Modern Physics”, Fourth Edition, Pearson Education, New Jersey, Tjuk Imawan, Materi Kuliah Pengantar Ilmu Fisika, Universitas Pembangunan Jaya, Tangerang Selatan, 2011