Energy EQ: What is the relationship between heat energy and temperature?

Eureka: Temperature

A. Definitions 1. Energy (light, heat, electric) The capacity to do work or supply heat.

A. Definitions 2. Law of conservation of energy: In any reaction, energy can be converted from one form to another, but cannot be created or destroyed.

A. Definitions 3. Heat (q) is the energy transferred always flows from Hot  Cold Measured in Joules or calories 4. Temperature (T) :measure of the avg. kinetic energy measured in Kelvin or degrees Celcius.

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule

Thermal energy can be transferred from object to object through direct contact Molecules collide, transferring energy from molecule to molecule AKA: HEAT

Eureka: Temp Vs. Heat

B. Unit conversions 1 cal = 4.184 J 1Cal = 1000 cal Convert 8.5 Joule to calories = 2.0 cal 1 cal 8.5 J x 4.184 J

C. Specific Heat (C) The amount of heat needed to raise the temperature of 1 gram of a substance by 1°C. Objects with low specific heats, heat up faster than objects with high specific heats. Which object heats up faster? Water: 4.184 j/gC Pot: 0.460 j/gC

∆T= Tfinal- Tinitial q = m x c x DT A. Specific Heat specific heat change in temperature Heat = mass X X q = m x c x DT ∆T= Tfinal- Tinitial

C for Fe = 0.444 J/g • 0C Given: q = ? Work: m = 869 g q=mcT Ex: How much heat is given off when an 869 g iron bar cools from 940C to 50C? C for Fe = 0.444 J/g • 0C Given: q = ? m = 869 g c = 0.444 J/goC ΔT = tfinal – tinitial = 50C – 940C = -890C Work: q=mcT q=869 g x 0.444 J/g0C x –890C q=-34,000 J

q_ c= ΔT =350C – 250C m∆T = 10.0C Given: Work: C= ? q=mcT  m= 25.0 g Ex: Calculate the specific heat of an object with a mass of 25.0 g whose temperature changes from 250C to 350C when 16,500 J are added. Given: C= ? m= 25.0 g ΔT =350C – 250C q = 16,500J Work: q=mcT  C = _16,500 J (25.0g) (10.0C) C = 66 q_ c= m∆T = 10.0C J/goC