Energy Transformations
PE/KE
Law of Conservation of Energy
Thermal Energy and Heat Transfer
Specific Heat and Heat Transfer
100
A runner eats breakfast, then goes on a jog. Which of the following energy transformations occurs during the jog?
A. Chemical to Mechanical
B. Mechanical to Chemical
C. Chemical to Light
D. Electrical to Chemical
A. Chemical to Mechanical
100
Which letter has the MOST potential energy?
Letter V
100
State the Law of Conservation of Energy.
Energy cannot be created or destroyed, but it can change from one form to another
100
If you place a hot piece of metal in a container of warm water, thermal energy flows from the metal to the water. What happens after the metal and the water reach the same temperature?
A. The flow of thermal energy stops, and the temperature remains the same.
B. The flow of thermal energy continues and causes both substances to become warmer.
C. The flow of thermal energy reverses and causes both substances to become warmer.
D. The flow of thermal energy reverses and the water becomes colder.
A. The flow of thermal energy stops, and the temperature remains the same.
100
Which statement describes how conduction occurs in this metal rod?
A. A convective flow of energy is set up inside the iron bar.
B. Energy is conducted from atom to atom along the length of the iron bar.
C. Radiation moves through the iron bar and is absorbed by the end not in the flame.
D. Air heated by the flame radiates down the iron bar and heats the end not in the flame.
B. Energy is conducted from atom to atom along the length of the iron bar.
200
Which of the following examples correctly explains the transformation from electrical to mechanical energy?
A. lightbulb - Electricity is being used to create light and heat.
B. space heater - Electricity is being used to create a chemical reaction.
C. toaster oven - Electricity is being used to create radiation
D. ceiling fan - Electricity is being used to spin the blades of the fan.
D. ceiling fan - Electricity is being used to spin the blades of the fan.
200
If all four books below have the same mass, which book has the greatest potential energy?
Book 2
200
What happens to the TOTAL ENERGY of the pendulum as it swings from position A to position E?
A. The total energy increases.
B. The total energy decreases.
C. The total energy stays the same.
D. The total energy increases and then decreases.
B. The total energy stays the same.
200
A student needed to explain how the sun's heat traveled to Earth. Which statement below should she choose to describe the transfer of energy from the Sun to the Earth?
A. The Sun is an extremely large source of thermal energy. Because of its size, the Sun can conduct its heat through space, heating the Earth.
B. The Sun uses nuclear fusion to create heat. The thermal energy it creates radiates through the vacuum of space and heats the Earth.
C. Heat flows from the Sun to Earth through convection currents. Earth's atmosphere traps and stores the heat.
D. Heat from the Sun requires matter to transmit the thermal energy to Earth. It is impossible for heat to flow from the Sun because an enormous vacuum exists between the Sun and Earth.
B. The Sun uses nuclear fusion to create heat. The thermal energy it creates radiates through the vacuum of space and heats the Earth.
200
According to the data table, if 200 J of energy were added to 1 g of each of these samples, which would experience the SMALLEST temperature increase and why?
Aluminum because it has the largest specific heat, which means it takes MORE energy to change
300
A group of campers build a bonfire by burning several logs. What state best describes the energy transformations that are taking place when the logs burn?
A. Chemical energy from the wood converts to light and heat energy
B. Heat energy from the logs is converted into chemical and light energy
C. Chemical energy from the air is converted into mechanical and light energy
D. Heat energy from the air is converted into mechanical and light energy
A. Chemical energy from the wood converts to light and heat energy
300
Which roller coaster will NOT have enough kinetic energy at the bottom of the first hill to carry the car over the second hill?
Hill C
300
What is happening to the TOTAL mechanical energy of the car as it travels to get more gas.
A. The total mechanical energy increases, decreases, then increases again
B. The total mechanical energy decreases
C. The total mechanical energy stays the same
D. The total mechanical energy increases
C. The total mechanical energy stays the same
300
During an investigation, two students placed three ice cubes in a glass of room temperature water. Which of the following scenarios would best describe the results of the investigation?
A. Cold from the ice cubes will transfer to the water, causing the water to cool.
B. Energy from the water will transfer to the ice cubes, causing the ice to melt.
C. Energy will transfer equally between the ice cubes and the water causing no change in temperature.
D. Cold is transferred from the ice/water mixture to the air, causing the air to cool.
B. Energy from the water will transfer to the ice cubes, causing the ice to melt.
300
A liquid thermometer is used to measure temperature. As the temperature changes, the liquid inside the thermometer expands and rises to show a higher reading Which of the following explanations best describes the changes in thermal energy of the particles during the heat transfer from the water outside the thermometer to the liquid inside the thermometer?
A. The tip of the thermometer is heated by radiation from the water outside the thermometer. The particles of the thermometer tip then transfer heat by convection to the liquid inside the thermometer.
B. The tip of the thermometer is heated by conduction from the water outside the thermometer. The particles of the thermometer tip then transfer heat by convection to the liquid inside the thermometer.
C. The tip of the thermometer is heated by convection from the water outside the thermometer. The particles of the thermometer tip then transfer heat by radiation to the liquid inside the thermometer.
D. The tip of the thermometer is heated by conduction from the water outside the thermometer. The particles of the thermometer tip then transfer heat by conduction to the liquid inside the thermometer.
D. The tip of the thermometer is heated by conduction from the water outside the thermometer. The particles of the thermometer tip then transfer heat by conduction to the liquid inside the thermometer.
400
The wheels of a toy car spin when its circuit is connected to a battery. Which sequence below correctly identifies the energy changes taking place in the car?
A. chemical to electrical to potential
B. chemical to electrical to mechanical
C. electrical to mechanical to potential
D. heat to mechanical to sound
B. chemical to electrical to mechanical
400
The two balls in the diagram below have an equal mass of 1 kg and are released from rest at the heights indicated. How does the potential energy of ball A compare to ball B?
Ball B has more PE because it it has more height
400
Using the Law of Conservation of Energy, which explanation best describes why bounce heights change with each bounce once a ball is released from a given height above the floor?
A. When the ball hits the floor, ALL of the energy is kept by the ball. Since the ball has NOT transferred any energy, it continues to bounce.
B. When the ball hits the floor, ALL of the energy is transferred to the floor. Since the ball loses its energy, it bounces lower and lower until it stops.
C. When the ball hits the floor, the ball gains energy. Thus, it is able to continuously bounce up off the floor.
D. When the ball hits the floor, energy is transferred into sound energy that you hear and thermal energy due to friction with the floor and the air. However, the ball keeps most of the energy, allowing it to continue to bounce for a while.
D. When the ball hits the floor, energy is transferred into sound energy that you hear and thermal energy due to friction with the floor and the air. However, the ball keeps most of the energy, allowing it to continue to bounce for a while.
400
A chef is making a package of ramen noodles and a pot of spaghetti. He uses two pots and adds the correct amount of 20 C water for each dish. He heats the small pot for 2 minutes on high and finds that the temperature is 100 C. He then heats the larger pot for 2 minutes on high. What will be true about the larger pot of water?
A. The temperature will be lower than 100°C
B. The temperature will be higher than 100°C.
C. The temperature will be equal to 100°C.
D. The temperature would not change
A. The temperature will be lower than 100°C
400
Chef A and Chef B use different pots to make their soup. Chef A used carbon steel and Chef B used copper. The first chef to bring their soup to a boil wins the competition. Who would win?
A. Chef A; because carbon steel has a higher specific heat than copper, it will allow the soup to reach boiling faster.
B. Chef B; because copper has a lower specific heat capacity than carbon steel, it will allow the soup to reach boiling faster.
C. Chef A; the carbon steel is a better conductor than copper because its specific heat capacity is higher than copper.
D. Chef B; the copper is a better insulator than carbon steel because its specific heat capacity is lower than carbon steel.
B. Chef B; because copper has a lower specific heat capacity than carbon steel, it will allow the soup to reach boiling faster.
500
Rocco and Hunter went on an evening walk. Rocco noticed that Hunter's flashlight was much dimmer than his flashlight. Which statement about energy transformations best explains why a flashlight becomes dimmer over time?
A. Electrical energy is transformed into electromagnetic energy. The lightbulb is losing its energy and burning out.
B. Chemical energy in the batteries transforms into electrical energy. The electrical energy is then transformed into heat and light. Over time, the chemicals in the battery are used up, causing the light to dim slowly.
C. The only energy transformation in a flashlight is chemical to electrical. The electric current was weaker in one flashlight because it was turned on longer.
D. The battery in one flashlight had leaked acid. Therefore, the electricity was not able to completely power the bulb.
B. Chemical energy in the batteries transforms into electrical energy. The electrical energy is then transformed into heat and light. Over time, the chemicals in the battery are used up, causing the light to dim slowly.
500
Objects can have kinetic energy, potential energy, or both. Energy can be in the form of motion. Energy can also be stored by objects in various ways, including position, chemical bonds, or physical state (solid, liquid, gas). Which of the statements below is true about energy?
A. An object's mass has no effect on its potential energy.
B. Potential energy is converted to kinetic energy as a stationary object begins to move.
C. Kinetic energy is converted to potential energy as a stationary object begins to move.
D. A stretched rubber band stores no energy.
B. Potential energy is converted to kinetic energy as a stationary object begins to move.
500
The energy stored in a wood log is transformed when the log is burned. Which of the following explanations best describes how the chemical energy stored in the log compares to the heat and light energy produced by burning?
A. The amount of chemical energy is equal to the amount of heat, light, and other applicable energies.
B. The amount of chemical energy is less than the amount of heat, light, and other applicable energies.
C. The amount of chemical energy is more than the amount of heat, light, and other applicable energies.
D. The amount of chemical energy stays the same, and additional energy is produced as heat, light, and other applicable energies.
A. The amount of chemical energy is equal to the amount of heat, light, and other applicable energies
500
Calorimeter A is filled with 100 mL of cold water and Calorimeter B is filled with 100 mL of hot water. A metal bar connects both containers. The heat is transferred from Calorimeter B to Calorimeter A through the process of:
A. Convection
B. Conduction
C. Radiation
D. Energy
B. Conduction
500
Which statement correctly explains the heat transfer as water moves through the water cycle?
A. The Sun's heat travels to Earth by conduction. The warm water vapor rises due to convection. The water vapor cooled due to radiation causing rain to fall back toward Earth.
B. The Sun's heat travels to Earth by radiation. The warm water vapor rises due to conduction. The water vapor cooled due to convection causing rain to fall back toward Earth.
C. The Sun's heat travels to Earth by convection. The warm water vapor rises due to radiation. The water vapor cooled due to conduction causing rain to fall back toward Earth.
D. The Sun's heat travels to Earth by radiation. The warm water vapor rises due to convection. The water vapor cooled so that it could fall back toward Earth.
D. The Sun's heat travels to Earth by radiation. The warm water vapor rises due to convection. The water vapor cooled so that it could fall back toward Earth.