Chapter 12: Forces and Motion - Section 12.4 Universal Forces

What are the four universal forces?

• Electromagnetic

• Strong nuclear

• Weak nuclear

• Gravitational

Is the following sentence true or false? Electromagnetic force is associated with charged particles.

• True

• False

The force that holds particles in the nucleus together is the ________.

• strong nuclear force

• weak nuclear force

• gravitational force

• electromagnetic force

The evidence that suggests nuclear forces have a powerful force of attraction is:

• The ability of nuclear forces to hold protons and neutrons together in the nucleus despite the repulsive electromagnetic force between protons.

• The ability of nuclear forces to repel protons and neutrons from the nucleus.

• The ability of nuclear forces to create new elements spontaneously.

• The ability of nuclear forces to prevent chemical reactions.

Over extremely short distances, approximately how many times stronger is the strong nuclear force than the electric force of repulsion?

• 10

• 100

• 1000

• 10,000

Compare and contrast the strong and weak nuclear forces. Both forces act within the nucleus of an atom to hold it together. The strong nuclear force affects only the neutrons and protons in the nucleus and acts over extremely short distances. The weak nuclear force acts over an even shorter distance but affects all particles, not just protons and neutrons.

• The strong nuclear force affects only neutrons and protons, while the weak nuclear force affects all particles.

• The weak nuclear force affects only neutrons and protons, while the strong nuclear force affects all particles.

• Both forces affect only neutrons and protons.

• Both forces affect all particles.

Circle the letter of each sentence that is true about gravitational force.

• The closer two objects are to one another, the weaker the gravitational force.

• The farther apart two objects are, the weaker the gravitational force.

• The greater the mass of an object, the stronger its gravitational force.

• Earth’s gravitational force is stronger than the gravitational force of the sun.

The sun’s mass is much greater than the mass of Earth, so the sun’s gravitational force is much _______ stronger _______ than that of Earth.

• stronger

• weaker

• equal

• less

Is the following sentence true or false? An artificial satellite in a high orbit will slow down and lose altitude due to the pull of Earth’s gravity. True or False?

• True

• False

Which of the following are uses of artificial satellites?

• Study Earth’s climate

• Monitor Earth’s weather

• Create detailed radar maps of Earth’s surface

• Use telescopes to gaze into space

• Receive and transmit radio and microwave signals