Energy Basics Energy Makes Everything Happen 3 You

Energy Basics

Energy Makes Everything Happen 3 You eat food Food provides the energy to work 3 A car drives Gasoline provides the power

Energy is divided into two types Depends on whether the energy is moving or stored

Types of Energy n Energy that is stored Potential Energy n Energy that is moving Kinetic Energy

Examples of Kinetic and Potential Energy

Units of Energy Measurement British Thermal Unit (BTU) Y Joule (J) Y

BTU The amount of heat needed to raise the temperature of one pound of water by 1 o. F n 1 Btu equals about: – One kitchen match n 1000 Btu equals about – 1 avg candy bar – 4/5 peanut butter & jelly sandwich n 2000 Btu equals about – the amount of energy to make a pot of coffee

Joule 948 joules = 1 Btu 4 It takes about 2 million joules to make a pot of coffee 4 1 joule is the amount of energy needed to lift one pound about 9 inches

Kilojoule (k. J) 1000 j= 1 k. J A piece of buttered toast contains about 315 k. J of energy. With that energy you could: ý Jog for 6 min. ý Bicycle for 10 min ý Sleep for 1. 5 hrs ý Run a car at 50 mph for 7 seconds ý Light a 60 watt light bulb for 1. 5 hrs

Energy cannot be created or destroyed Enery can only be changed from one form into another form of energy

Some Energy Interconversions n n Stored energy in a flashlight’s batteries becomes light energy when turned on Food contains energy stored as chemical potential energy. Your body uses the stored energy to do work. Overeating stores food energy as potential energy in the form of fat When talking on the phone, your voice is changed into electrical energy. The phone on the other end changes the electrical energy into sound energy.

Categories of Primary Energy Z Energy Income (Renewable resources) – resources being continuously regenerated Z Energy Capital (Non-renewable) – use of such resources permanently reduces the quantity

Available Energy Sources Renewable – – – – Hydroelectric energy Tidal forces Biomass Geothermal heat Wind Solar input Ocean thermal gradients Non-renewable – – – Crude oil Natural gas Coal Nuclear fission Synthetic oil

Global Energy Fluxes

Primary Energy Consumption World consumption has increased more than 10 fold in 20 th Century Causes: n World population grew 2. 5 fold n Increased mechanization in industrialized countries

Historical Trends in Energy Consumption