Understanding Temperature and Its Impact on Daily Life

Slide1Unit 2: HeatChapter 4:  Temperature describes how hot or cold an object is.

Slide2How does temperature affect your daily life?  Why do you feel warm playing outside on a cold winter’s day?

Slide3Place one hand incold water, one hand in “hot” water for 1 minute.  Then at the same time put both hands in the luke warm water. Describe what each hand feels.

Slide4How hot or cold something is

Slide6The human body

Slide7Boiling point of water  Freezing Point of water

Slide8Comfortable room temperature

Slide91. Galileo’s AirThermoscope : As the air heats, the liquids drops and rises when air is cooled. Early Thermoscopes...

Slide102. Early LiquidThermometer : Liquid rising up the tube shows the temperature is rising.

Slide11Activity 4-1A“Building a Thermoscope” Page 121

Slide12Scales are necessary for temperatures to be accurate and comparable.

Slide133 commonly used scalesare: 1. Fahrenheit 2. Celsius 3. Kelvin

Slide14Developed by Daniel Fahrenheit  The first to be widely used

Slide15Developed by Anders Celsius.  Based on the freezing and boiling points of water.

Slide16Developed by William Thomson (Lord Kelvin)  Scale starts that the coldest temperature possible –  absolute zero (-273  ˚ C)

Slide181. The Liquid-in-glassThermometer The lab thermometer contains colored alcohol rather than mercury for safety.

Slide192. The Thermocouple Made of two wires of different metals.  A temperature difference causes a current to flow through the wires.  This current is measured by a meter.

Slide20Can measure higher temperatures than typical thermometers.

Slide213. The ResistanceThermometer ( digital thermometers )

Slide224. Bimetallic Strip( thermostat )  Made of two different metals fused together.  These metals expand and contract at different rates causing the strip to bend when heated.

Slide23Thermostat

Slide24Heating and Coolinga Bimetallic Strip

Slide255. Infrared Thermometer( thermogram )  Converts infrared radiation into colors that can interpret a temperature difference.

Slide26Can beused to measure heat loss in your home