Energy assignment and quiz

According to the law of conservation of energy, what will most likely happen in a closed system? Energy will be exchanged along with matter. Energy will be exchanged, but matter will not be exchanged. Energy will be created along with matter. Energy will be destroyed, but matter will not be destroyed.

Energy will be exchanged, but matter will not be exchanged.

What happens to energy when Sally kicks a soccer ball? Kinetic energy is transformed to chemical energy in muscles. Potential energy is transformed to chemical energy in muscles. Kinetic energy is transferred from the leg to the soccer ball. Potential energy is transferred from the leg to the soccer ball.

Kinetic energy is transferred from the leg to the soccer ball.

Which is the best term to use when describing the energy of motion? chemical kinetic potential thermal

kinetic

In a chemical reaction occurring in an open beaker, the reactants have a mass of 10.0 g and contain 1000 J of energy. The products in the beaker contain a mass of 5.0 g and 500 J of energy. Which best explains the difference in energy and mass as reactants are converted to products? kinetic energy closed systems law of conservation electromagnetic energy

law of conservation

As gravity makes an object fall down toward the ground,.... energy becomes kinetic energy.

potential

Which is the best example of potential energy? holding a basketball in the air rolling a ball across a flat table flowing electric current through a wire turning on a flashlight in a dark room

holding a basketball in the air

Which statement describes thermal energy? the energy that is associated with electric fields the energy that is stored in chemical bonds the energy that is associated with the pull of gravity the energy that is associated with temperature

the energy that is associated with temperature

Consider the generic chemical equation below. X + Ymc021-1.jpg W + Z Reactant X contains 199.3 J of chemical energy. Reactant Y contains 272.3 J of chemical energy. Product W contains 41.9 J of chemical energy. If the reaction loses 111.6 J of chemical energy as it proceeds, how much chemical energy must product Z contain? 318.1 J 429.7 J 541.3 J 625.1 J

318.1 J

A welding torch produces a flame by burning acetylene fuel in the presence of oxygen. The energy released from the acetylene fuel is then used to melt a metal. Which energy transformation happens during this process? Chemical energy turns into thermal energy. Kinetic energy turns into potential energy. Thermal energy turns into electromagnetic energy. Potential energy turns into chemical energy.

Chemical energy turns into thermal energy.

Chemical energy in burning wood is changed into thermal energy. The thermal energy is absorbed by water, which boils to produce steam. The thermal energy is changed into kinetic energy in the moving steam. The kinetic energy is used to turn a turbine, which converts the kinetic energy into electricity. Which sentence best describes this system? It involves only energy transfer. It involves only energy transformation. It involves both energy transformation and energy transfer. It does not involve either energy transformation or energy transfer.

It involves both energy transformation and energy transfer.

A generator contains a coil that spins to produce an electric current. How is energy transformed by using a generator? Thermal energy is transformed to potential energy. Thermal energy is transformed to mechanical energy. Chemical energy is transformed to electromagnetic energy. Mechanical energy is transformed to electromagnetic energy.

Mechanical energy is transformed to electromagnetic energy.

An arrow is fired by a person on the ground 15 feet away from a target 20 feet high on a wall. Which statement correctly describes the change in the energy of the arrow as it moves toward the target? The potential energy and kinetic energy remain the same. The potential energy decreases as kinetic energy increases. The kinetic energy decreases as potential energy increases. The kinetic energy remains at zero, but potential energy increases.

The kinetic energy decreases as potential energy increases.

Consider the following generic chemical equation: A + B → C + D Reactant A contains 85.1 J of chemical energy. Reactant B contains 87.9 J of chemical energy. Product C contains 38.7 J of chemical energy. If the reaction absorbs 104.3 J of chemical energy as it proceeds, how much chemical energy must product D contain? Explain your answer.

Which of these did you include in your answer? The law of conservation of energy states that energy is not created or destroyed during chemical reactions. The total amount of energy in the reactants, plus the energy absorbed during the reaction, must be equal to the total energy of the products. Product D contains (85.1 J + 87.9 J + 104.3 J) - 38.7 J = 238.6 J of chemical energy.

Describe the energy transfers and transformations that occur when a person rides a bicycle. Make sure to identify each example as an energy transfer or an energy transformation.

Which of these did you include in your answer? chemical energy transformed to kinetic energy in muscles and/or body kinetic energy transferred from legs to pedals kinetic energy transferred from pedals to wheels kinetic energy transformed to thermal energy due to friction (wheels get warm) chemical energy transformed to thermal energy in muscles

Choose the best answer to each question. Which has the most kinetic energy? Which has the most thermal energy? Which has the least gravitational potential energy?

a bowling ball with a velocity of 1.5 m/s a lake at 10 degrees C a 10 kg barbell resting on the floor

Old photographic flashbulbs burn magnesium metal in a reaction that causes a flash of brilliant white light. A photographer would need to take care not to suffer burned fingers when trying to replace the hot bulb. What best identifies the energy transformation that occurs in the flashbulb? chemical energy to electromagnetic energy and thermal energy electromagnetic energy to chemical energy and thermal energy chemical energy to electromagnetic energy thermal energy to chemical energy

chemical energy to electromagnetic energy and thermal energy

A baseball player hits a ball. Which is the best description of the energy of the ball as it flies over the pitcher's head? chemical mechanical kinetic thermal

mechanical

In a mechanical clock, the swinging of a pendulum causes the hands to move. The diagram shows the path of the pendulum as it swings. At which point in its swing does the pendulum have the least gravitational potential energy? point A point B point C point D

point C

Which is the best term to use when describing the energy of position? chemical kinetic potential electromagnetic

potential

What is the main form of energy represented by each of the following? A spring is compressed. Oxygen bonds with carbon. An electron generates an electric field. A soccer ball rolls along the grass.

potential energy chemical energy electromagnetic energy kinetic energy