Question

1. p.331 what is the name of the force that two surfaces exert on each other when they rub against each other? 7. p.331 what two factors determine the amount of friction that will exist between two surfaces? 8. p.332 what does it mean when forces can act at a distance (non - contact)? 9. p.332 describe gravitational force. 10. p.333 what is the law of universal gravitation?

Explanation:

1. Friction is the force that resists the relative motion of two surfaces in contact.
2. The two factors determining friction are the nature of the surfaces (smoothness/roughness) and the force pressing the surfaces together.
3. Non - contact forces are forces that act on objects without physical contact, like gravitational, magnetic and electrostatic forces.
4. Gravitational force is the force of attraction between two masses. It is proportional to the product of the masses and inversely proportional to the square of the distance between their centers.
5. The law of universal gravitation states that every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers, expressed as \(F = G\frac{m_1m_2}{r^2}\), where \(F\) is the gravitational force, \(G\) is the gravitational constant, \(m_1\) and \(m_2\) are the masses of the two objects, and \(r\) is the distance between their centers.

Answer:

1. Friction
2. Nature of surfaces, force pressing surfaces together
3. Forces acting without physical contact (e.g., gravitational, magnetic, electrostatic)
4. Force of attraction between two masses, proportional to product of masses and inversely proportional to square of distance between centers
5. Every particle attracts every other particle with a force \(F = G\frac{m_1m_2}{r^2}\)