Heat

Which of the following is a source of heat?

• 
• 
• 
• 

Which of the following is not a source of heat?

• 
• 
• 
• 

Which one of the following statements about heat is NOT true?

• Heat cannot be seen.

• Heat is a form of energy.

• Heat keeps living things warm.

• Heat travels from a colder place to a hotter place.

Study the graphs below carefully. 

Which one of the following graphs best represents the change in temperature of a cup of hot chocolate left in a classroom for an hour?

• 
• 
• 
• 

Lynn placed a metal rod in a glass of hot water.

The rod became hotter after a while.

 

Which one of the following explains this?

• The glass loses heat to the hot water.

• The hot water gains heat from the rod.

• The rod gains heat from the hot water.

• The rod loses heat to the hot water.

Lynn placed a metal rod in a glass of cold water.

The rod became colder after a while.

 

Which one of the following explains this?

• The metal rod gained heat from the cold water.

• The cold water gained heat from the metal rod.

• The glass gained heat from the cold water.

• The cold water lost heat to the metal rod.

In a wooden box, objects P and Q are placed touching each other.

Heat flows from P to Q.

Which statement explains why heat flows from P to Q?

• P has more mass than Q.

• P is at a higher position than Q.

• P is at a higher temperature than Q.

• P is a better conductor of heat than Q.

Eric has two cups, A and B, made of material P. He poured an equal amount of hot water into each cup. Cup A was too hot to hold but he can hold cup B easily as shown.

Which of the following best explains why Eric can hold cup B easily but not cup A?

• Cup A is a good conductor of heat.

• Cup B is a poor conductor of heat.

• Distance from heat source is further in cup B.

• Cup A is a good conductor of heat but the handle of cup B is not.

Meimei heated some buns with a liquid filling as shown in Diagram 1.

After a while, the filling burst through the wall of the bun as shown in Diagram 2.

Which of the following best explains why?

• The wall of the bun is not waterproof.

• The filing expanded more than the bun.

• The filing is hotter than the bun.

• Air trapped in the wall of the bun expanded.

Sulaiman placed two empty identical containers, K and M, both initially at room temperature on a table. He poured 500cm³ of boiling water into container K and 250cm³ of boiling water into container M.

The temperatures of water in K and M were recorded every minute for some time.

Which one of the following is the correct graph for his results?

• 
• 
• 
•