Heat

Which material is the best conductor of heat?

• glass

• rubber

• metal

• wood

After holding an ice pack on his skin for 20 minutes, the man notices the ice pack is melting.

Why is this happening?

• radiation - the ice pack is now all melted

• conduction - body heat transferred to the cold ice pack

• convection - the water in the ice pack flowed in a circle pattern

• conduction - heat came from the bigger object to the smaller

Conduction can only occur between two objects when –

• one object is less dense than the other

• both objects are in thermal contact with each other

• one of the objects is made of a metal

• both objects are exactly the same temperature

When holding a cup of ice water, your warm hand becomes cold. How does the heat transfer?

• From the cold cup to your hand

• From the cold cup to the warm air

• From the ice to your hand

• From your warm hand to the cold cup

What kind of heat transfer is occurring when the sun warms the sand?

• Conduction

• Convection

• Radiation

• All of them

Which of the following is true when a substance is melting?

• The temperature remains constant

• Both a solid and a gas can be present

• Heat is not required for the process since the temperature is constant

• The heat added is causing the particles to change from a high energy state to a low energy state

If 900 J of heat are added to 100.0 g of water at 25.0°C. What is the final temperature of the water?

• 27.15 °C

• 2.15 °C

• 25.0 °C

• 3.00 °C

Which of the following best explains why the sand at the beach is hotter than the water?

• Sand has a higher specific heat capacity than water

• Sand has a lower specific heat capacity than water

• There is more water than sand at the beach

• There is more sand than water at the beach

Which of the following is the best example of conduction?

• A light bulb warming a lampshade

• An egg cooking in a frying pan

• Water boiling in a pot

• Gases circulating in the atmosphere

Why do metal pans often have wooden handles?

• Metal heats slower than wood

• Wood does not conduct heat as well as metal

• Metal gets heavier as it is heated

• Wood burns to make heat and metal does not