PS 04.3 TB Conservation of Energy

The law of conservation of energy states that energy cannot be ______ or destroyed, only transformed from one form to another.

Answer explanation

The law of conservation of energy states that energy cannot be created or destroyed, only transformed. Therefore, 'created' is the correct choice to fill in the blank.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which of the following is an example of energy transformation?

• A) A car engine converting fuel into motion

• B) A book on a table

• C) A stationary rock

• D) A glass of water

Answer explanation

A car engine converting fuel into motion is an example of energy transformation, as it changes chemical energy from fuel into kinetic energy for movement. The other options do not involve any energy transformation.

Fill in the blank: The total energy of an isolated system remains ______ over time.

Answer explanation

The total energy of an isolated system remains constant over time due to the law of conservation of energy, which states that energy cannot be created or destroyed, only transformed.

What is the law of conservation of energy?

Answer explanation

The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. This principle is fundamental in physics, ensuring that the total energy in a closed system remains constant.

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Mechanical energy is the sum of potential energy and (a)   .

• Kinetic energy

• Thermal energy

• Chemical energy

• Electrical energy

Answer explanation

Mechanical energy consists of potential energy and kinetic energy. Kinetic energy is the energy of motion, making it the correct choice to complete the statement.

Fill in the blank: The mechanical energy of an object is the sum of its kinetic energy and ________.

Answer explanation

The mechanical energy of an object is the sum of its kinetic energy and potential energy. Kinetic energy is the energy of motion, while potential energy is stored energy based on position. Thus, the correct answer is potential energy.

Tags

NGSS.MS-PS3-2

Which of the following best describes friction?

• A force that attracts objects to each other

• A force that opposes the sliding motion of two surfaces that are touching each other

• A force that causes objects to move faster

• A force that has no effect on motion

Answer explanation

Friction is defined as a force that opposes the sliding motion of two surfaces in contact. It acts to resist movement, making the correct choice the one that describes this opposing force.

Energy can only be converted from one form to another or transferred from one place to another. (True/False)

• True

• False

Answer explanation

The statement is True because energy cannot be created or destroyed; it can only change forms (like kinetic to potential) or be transferred (like heat from one object to another).

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

The form of mechanical energy changes, but the total amount of mechanical energy (a)   the same.

• increases

• decreases

• remains

Answer explanation

The total mechanical energy remains the same due to the conservation of energy principle. While the form of energy may change (e.g., from potential to kinetic), the overall amount of mechanical energy is conserved.

Fill in the blank: At the highest point of the ball's trajectory, the kinetic energy is _____ and the gravitational potential energy is high.

Answer explanation

At the highest point of the ball's trajectory, it momentarily stops before falling back down, resulting in zero kinetic energy. However, gravitational potential energy is at its maximum due to the height.

Tags

NGSS.MS-PS3-2