Energy unit assessment / Mid Term

Name (first and last)

Sunlight passes through the windows of a car and causes the car seats to get hot. Which type of energy flow is involved in heating the seats?

• conduction
• convection
• insulation
• radiation

Which picture below shows the transfer of heat by conduction?

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The BEST example of heat transfer by convection is when

• sunlight warms soil
• a fan blows air
• flames heat up a frying pan
• heat rises in a chimney

Which of these materials transfers heat energy quickest?

• metal
• glass
• plastic
• wood

Hot objects begin to cool as

• cooler air is transferred to the object.
• energy in the object is transferred to the surrounding air.
• atoms in the object react with the oxygen in the air.
• energy in the object cancel out energy in the air.

Which of the following statements about thermal energy is true?

• As you hold a cup of hot water your hands cool the water.
• As you hold a glass of cold milk, the cold travels to your hand.
• As you hold a cup of cold milk, your hand cools the milk.
• As you hold a cup of hot water, the heat moves to your hand.

Which of these factors affects how fast a sound wave moves?

• The kind of material it is moving through.
• The amplitude of the sound wave's vibrations
• The wavelength of the disturbance in the medium
• The type of motion that caused the sound wave to form.

In an investigation, water in a flask is placed on a hot plate. As the water is heated, the cooler, denser water at the surface sinks and pushes the warmer water to the top. What do the arrows in the drawing MOST likely represent?

• phase changes
• convection currents
• electromagnetic radiation
• energy transfer by conduction

Why does a leaf look green in the summer?

• The leaf absorbs green light.
• The leaf produces green light in its cells.
• The leaf uses green light to make food in its cells.
• The leaf reflects green light and absorbs other colors of sunlight.