Energy and Work: A Physics Challenge

According to the principle of conservation of energy, which of the following statements is true?

• AEnergy can be created but not destroyed.
• BEnergy can be destroyed but not created.
• CEnergy can be both created and destroyed.
• DEnergy is neither created nor destroyed, only transformed.

When is the work done by a force considered to be zero?

• AWhen the force is applied in the same direction as the displacement.
• BWhen the force is applied in the opposite direction of the displacement.
• CWhen the force is applied perpendicular to the displacement.
• DWhen the force is applied at a 45-degree angle to the displacement.

What is the relationship between kinetic energy and the work done by a motive force?

• AThe work done by a motive force is always negative and decreases kinetic energy.
• BThe work done by a motive force is always positive and increases kinetic energy.
• CThe work done by a motive force is always zero and does not affect kinetic energy.
• DThe work done by a motive force can be positive or negative, depending on the direction.

According to the principle of conservation of mechanical energy, what happens to the potential energy of a body as it moves in the absence of friction?

• AIt remains constant.
• BIt is entirely transformed into kinetic energy.
• CIt is lost as heat.
• DIt is partially transformed into kinetic energy and partially lost as heat.

What does the zeroth law of thermodynamics state?

• AEnergy is conserved.
• BThe entropy of an isolated system always increases.
• CWhen two bodies are in thermal equilibrium with a third body, they are in thermal equilibrium with each other.
• DThe absolute zero of temperature cannot be reached in a finite number of steps.