PIC NEEDED
being able to transfer energy (thermal, electricity, sound) Jan 23 / 24 Act D 59 Ice Melting Contest LEARNING TARGET: I can identify methods to maximize thermal energy transfer. CH Q How can you increase the energy transferred to an ice cube? VOCAB: Conduction / conductor being able to transfer energy (thermal, electricity, sound)
PROCEDURE AND DATA MATERIALS: PROCEDURE: Read on pg. D 37 and summarize DATA: Notes in Journal Pre-Lab Thought: What would be the best method for the control? set up a bag with same sized / shaped ice cube and do NOT do anything to it
You may not put the ice or the bag in your mouth. ICE-MELTING RULES You may not put the ice or the bag in your mouth. Keep ice cube in plastic bag until end of contest. Handle bags carefully. (broken bag disqualifies you) Keep ALL water in bag. (spills cannot be measured) Watch carefully for teacher’s START/STOP signals. As soon as the contest time is up, remove the remaining ice from the plastic bag - place it in the cup provided, and set it aside.
POST DISCUSSION Did you alter the way you melted your ice cube during the 3 minutes? If so how? How much water (mL) did you melt with you methods?
POST DISCUSSION Discuss and list all the variables that affected how fast the ice melted. If you did this next time, what would you change? 1. conducted heat (from body, table, sink, air) 2. surface area (more area = more melting) 1. stronger bags 2. all ice cubes same size 3. all liquids collected same time
True or False: The ice made your hands cold, because the ‘cold’ was transferred to you hands. False: Your hands were cold because of the loss of thermal energy from your hands to the ice. (you gave your heat away) *Hot things Have the energy – so it moves from them to the cold things
Things are cold when there is an absence of thermal energy Similar concept Light is a form of energy… Darkness is simply the absence of light. Things are cold when there is an absence of thermal energy No such thing as ‘cold’
Reminder: What is temperature?? It is the movement of particles. The faster the particle movement the more thermal energy… the warmer it is. The slower the particle movement the less thermal energy, the ‘colder’ it is.
ANALYSIS - Discuss and answer Q 2 & 3 on pg.D 38 ANS CH Q How can you increase the energy transferred to an ice cube? A: 1. increase surface area 2. increase temperature conducted 3. add other energy sources: infrared (heat) light HOMEWORK Bring items that could be used as insulators Bring Next class !!!!! - NOT a commercial insulator - thermos / cooler / etc