# Topic: Heat Flow

Topic: Heat Flow

Pre-Assessment

1. Anna pours herself some room-temperature soda from a bottle and adds four ice cubes. In a few minutes the ice cubes are smaller and the soda is much colder. Which of the following best explains the change in temperature of the soda?

1. Heat flowed from the soda to the ice cube and caused it to partially melt.
2. Coldness flowed from the ice cube to the soda, making the soda colder.
3. The cold water from the melting ice went into the soda, replacing the warmer water that was in the soda.
4. The water from the melting ice makes the soda more dilute, and the lower concentration makes the temperature lower.

2. Jeffery brings a book from air-conditioned apartment to a balcony on a hot summer day. How will the cool book interact with the outside air?

1. Heat from the book will move to the air.
2. Heart from the air will move to the book.
3. Coolness from the book will move to the air.
4. Coolness from the air will move to the book.

Heat Transfer Lab

Experiment Question

 What happens when a flask of hot water is placed inside a beaker of cold water?

Hypothesis

 If ______, then ______.

Materials

• 500 mL beakerHot plate
• Ring standThermometers x2
• Utility clamp Stop watch

Procedure

1. Heat up 125 mL of water in the flask to boiling.
2. Add 400 mL of water and 10 pieces of ice to the 500 mL beaker.
3. Record the temperature of the water in the flask and the temperature of the water in the beaker in the data table. This is zero minutes.
4. Use the utility clamp to secure the flask to the ring stand. Position the flask so that the body of the flask is submerged in the cold water in the beaker. Take a look at the example on the board.
5. Start the stop watch and record the temperature of both liquids at one minute intervals in the data table below up to ten minutes.

Data:

Time (minutes) / Temperature (°C) of Water in Flask / Temperature (°C) of Water in Beaker

Graph

Lab Questions

1. Answer the experiment question. Use evidence.
1. Does the evidence support your prediction? Explain. Resolve any inconsistencies by discussing with your group members.
1. So what happened in terms of energy? Was there a transfer of energy? If so, describe the transfer. How were you able to observe the transfer?

Assessment

1. Vanessa told her friend Kathy about a recent visit to her doctor for her annual physical exam. Vanessa explained that she shivered when the doctor placed a stethoscope against her skin. Why did Vanessa shiver?
1. Energy as heat flowed from the stethoscope to Vanessa’s skin.
2. Energy as heat flowed from Vanessa’s skin to the stethoscope.
3. Vanessa’s skin was cooler than the stethoscope.
4. The stethoscope transferred cold to Vanessa’s skin.
1. Melissa burned her hand when she touched a hot pan as illustrated below. What method of heat transfer was responsible for this accident?
1. thermal conduction
2. thermal convection