Understanding Mass and Energy

What is the core lesson of the equation E=mc²?

• Mass is a form of energy.

• Mass is an indicator of the amount of matter.

• Mass is a property of energy.

• Mass can be converted to energy.

Why does a running watch have more mass than a stopped one?

• It has more matter.

• It is heavier due to gravity.

• It has more kinetic, potential, and thermal energy.

• It has more atoms.

What does the term 'rest mass' refer to?

• Mass when an object is moving.

• Mass when an object is at rest.

• Mass that is always constant.

• Mass that changes with speed.

How does turning on a flashlight affect its mass?

• The mass decreases.

• The mass doubles.

• The mass remains the same.

• The mass increases.

What happens to the mass of the sun as it shines?

• It increases.

• It decreases.

• It doubles.

• It remains constant.

How does the mass of a closed box with a flashlight inside change when the flashlight is turned on?

• The mass doubles.

• The mass remains the same.

• The mass decreases.

• The mass increases.

Why does the mass of a hydrogen atom weigh less than its parts?

• Because of positive potential energy.

• Because of thermal energy only.

• Because of kinetic energy only.

• Because of negative potential energy.

What contributes to the mass of protons and neutrons?

• Quark potential energy.

• Only the mass of quarks.

• The mass of gluons.

• The mass of electrons.

What is the main takeaway about mass from the video?

• Mass can be converted to energy.

• Mass is an indicator of the amount of matter.

• Mass is always constant.

• Mass is a property of energy.

What is the challenge question about?

• The mass of a flashlight.

• The mass of a hydrogen atom.

• The mass of the sun.

• The mass of the Earth when everyone picks up a hammer.