An object falls through the air, gaining speed as it falls. A student claims that this creates new energy, and so it breaks the law of conservation of energy.

Question

An object falls through the air, gaining speed as it falls. A student claims that this creates new energy, and so it breaks the law of conservation of energy.
Which statement describes why the student is incorrect? (1 point)
• Energy can be created without breaking the law of conservation of energy.
• Speed is not related to energy in any way.
• Energy is converted from other forms, not created.
• Equal and opposite amounts of other energy are also created.

GPT-4o mini · Answer

The correct statement that describes why the student is incorrect is:

• Energy is converted from other forms, not created.

When an object falls through the air, it converts gravitational potential energy into kinetic energy. The total energy in the system remains constant, adhering to the law of conservation of energy.

AYD3N · Answer

A person throws a ball up into the air, and the ball falls back toward Earth. At which point would the kinetic energy be the lowest? (1 point)
• at a point before the ball hits the ground
• when the ball is at its highest point
• when the ball leaves the person's hand
• at a point when the ball is still rising

GPT-4o mini · Answer

The point at which the kinetic energy of the ball would be the lowest is:

• when the ball is at its highest point.

At the highest point, the ball's velocity is momentarily zero before it starts to fall back down, which means its kinetic energy is also at its lowest at that moment (while its potential energy is at its maximum).

AYD3N · Answer

A book is at rest on a flat table. A person gives the book a shove and it slides across the table. The book eventually comes to rest again near the edge of the table. How does the potential and kinetic energy change during this process? (1 point)
The potential stays the same since the book is on the table. The kinetic energy stays the same since the book was only shoved.
The potential and kinetic energy are the same while the book is sitting on
• the table. They both increase when the book is shoved and then decrease as the book comes to rest again.
The potential energy will stay the same as long as the book stays on the table. The kinetic energy increases when the book is shoved and then gradually decreases as it slides across the table and then comes to rest on the edge.
The potential energy increases as the book is pushed across the table. The kinetic energy stays the same since the book was shoved.

GPT-4o mini · Answer

The correct statement regarding the changes in potential and kinetic energy during the process is:

• The potential energy will stay the same as long as the book stays on the table. The kinetic energy increases when the book is shoved and then gradually decreases as it slides across the table and then comes to rest on the edge.

When the book is shoved, its kinetic energy increases due to the applied force. As it slides and eventually comes to rest, the kinetic energy decreases due to friction and other forces acting on it. Meanwhile, the potential energy remains constant as long as the book stays at the same height on the table.

AYD3N · Answer

Which is a good description of potential energy? (1 point) • conserved energy • stored energy • energy of motion • energy of reaction

GPT-4o mini · Answer

A good description of potential energy is:

• stored energy.

Potential energy refers to energy that is stored in an object due to its position or state, such as an object raised to a certain height (gravitational potential energy) or a compressed spring (elastic potential energy).