Heat/ Temperature/ Energy Test

A scientist places a block of metal in a jar of cool water. Because energy is converted, what MUST happen?

• The sum of thermal energy of the water and the thermal energy of the metal increase.

• The thermal energy of water and the thermal energy of the metal will remain the same.

• Some of the metal’s thermal energy is transferred to the water as heat, but a small amount of mass change.

• The thermal energy of the water will increase by the same amount that the thermal energy of the metal decreases.

A scientist performed an experiment and measured the energy transfer in each step of her experiment. The total quantity of energy transferred in all of the steps was less than what she had at the beginning. What is the MOST LIKELY explanation for this result?

• The energy was destroyed in the process of conduction the experiment

• The experiments required more energy than what was available

• The experiments created energy that was then used up at a faster rate

• Some energy was transferred into unwanted heat or sound that was not detected

Which scenario BEST explains the Law of Conservation of Energy?

• All of the energy used to throw a ball is lost when it lands

• When a fish uses all of its energy it creates more by swimming less

• As a toy car moves all of its energy is released into the ground

• Plants convert all of the energy they absorb from the sun into energy needed to make their own food

Which of the following statements is true about the energy of the pendulum as it moves from position 1 to position 5?

• Total amount of energy changes during the swing of pendulum

• The amount of potential and kinetic energy remains constant during the swing of the pendulum

• As the amount of kinetic energy decreases, the amount of potential energy increases, but the total amount of energy remains the same

• As the amount of kinetic energy decreases, the amount of potential energy also decreases, but the total amount of energy remains the same

If you cook pizza in a microwave oven, electromagnetic waves warm the pizza, not heat from the surrounding air. Which type of heat transfer cooks a pizza in a microwave oven?

• Radiation

• Insulation

• Conduction

• Convection

The image below shows a tea kettle on a gas stove. Which statement describes the energy transformations that occur when the tea kettle begins to whistle as hot water is heated on a stove that uses natural gas?

• The thermal energy in the natural gas is transferred into sound energy when the water becomes hot. Then the sound energy changes into light energy when the kettle becomes warm

• The chemical energy in the natural gas is transformed into thermal energy which heats the water. Then the thermal energy changes into sound energy when the water forms steam and the steam leaves the kettle

• The light energy in natural gas is transformed into chemical energy in the water. Then the chemical energy changes into kinetic energy when steam leaves the kettle and into sound energy when the water boils

• The electrical energy in the natural gas is transformed into thermal energy which causes the water to form steam. Then the thermal energy changes into sound energy and light energy when the steam leaves the kettle

Why did the sand burn my feet?

• Thermal energy is transferred from my feet to the hot sand

• Mechanical energy is transferred from my feet to the sand

• Kinetic energy from my feet is transferred to the hot sand

• Thermal energy is transferred from the hot sand to my feet

You probably use the term heat many times a day. As an example, when you cook dinner, you heat your dinner on a stove. When you place a piece of cool metal in the sun, it is heated by the sun’s energy. Why is heat the correct term to use in these examples?

• They show that when objects are touching, they are the same temperature.

• They show that heat flows from something warmer to something cooler.

• They indicate that heat is created to raise the temperature of something.

• They indicate that the kinetic energy of the particles decreases when something is heated.

Energy is conserved within a system, meaning that forms of energy are either transferred or transformed as they interact with objects. Which of the statements below correctly describe how energy is transferred or transformed in daily life?

• Nuclear energy is transferred to electrical energy to provide electricity for our homes.

• Kinetic energy transforms into thermal energy when a heating pad is turned on.

• Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street.

• Electrical energy is transferred into light energy so that a flashlight generates light when it’s turned on.

When a boy and his friends arrive at a barbecue, they offer to help their friend cook. They place meat and vegetables from the refrigerator onto the hot grill. When the food is cooked and taken off the grill, it is at a much higher temperature than it was before it was cooked. Which statements are true about the food? Choose the two that apply.

• A. The kinetic energy of the food particles increased, causing the food temperature to rise.

• B. The thermal energy of the food increased.

• C. The kinetic energy of the food particles decreased, causing the food temperature to rise.

• D. The thermal energy of the food decreased.