Physics Chapter 2: Force and Friction Flashcards

Questions and Answers

Define force.

The difference between a contact force and non-contact force. Examples include a push (contact) and gravitational pull (non-contact).

What is the difference between a contact force and non-contact force?

A contact force is applied by bodies in physical contact, while a non-contact force acts without physical contact.

What is the SI unit for force?

Newton or N

Define gravity.

The force that attracts an object. Signup and view all the answers

Explain the Law of Universal Gravitation.

A particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Signup and view all the answers

What two things does gravity depend on?

Mass and distance Signup and view all the answers

What effect does distance have on gravity?

As distance increases, the force of gravity decreases. Signup and view all the answers

What is the relationship between mass and weight?

Mass is a measure of the amount of matter in an object, while weight is the force exerted on an object by gravity. Signup and view all the answers

What is friction?

The resistance that occurs when two surfaces interact. Signup and view all the answers

What are ways to reduce friction?

Using bearing surfaces that are sacrificial, such as low shear materials. Signup and view all the answers

Study Notes

Force and Friction

Definition of Force: A contact force is applied by a body in direct contact with another, while a non-contact force acts without physical contact.
Examples of Force Types:
- Contact Force: Friction, tension, normal force
- Non-Contact Force: Gravitational force, electromagnetic force
SI Unit of Force: Newton (N)
Definition of Gravity: A force that attracts objects towards one another, specifically towards the center of the Earth.
Law of Universal Gravitation: Every particle in the universe attracts every other particle. The force is proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
Factors Affecting Gravity:
- Mass: The greater the mass, the stronger the gravitational force.
- Distance: Greater distance between objects results in weaker gravitational force.
Effect of Distance on Gravity:
- Doubling one mass leads to a doubling of gravitational force.
- Increasing distance decreases the strength of gravitational attraction.
Mass vs. Weight:
- Mass measures the amount of matter in an object, representing its inertia.
- Weight measures the gravitational force acting on an object, causing it to accelerate downwards.
Definition of Friction: A resistive force caused by the interaction of rough surfaces. The rougher the surfaces, the greater the frictional force.
Examples of Friction:
- Sliding friction when two surfaces slide past each other
- Static friction that prevents motion between surfaces at rest
Ways to Reduce Friction:
- Use of lubricant materials (like grease or oil)
- Implementing bearing surfaces made of low-shear materials (e.g., lead/copper journal bearings).

Description

Test your knowledge on force and friction with these flashcards. Explore the differences between contact and non-contact forces through definitions and examples. Perfect for students studying physics concepts in Chapter 2.