Chapter 1-10: Introduction to Forces and Motion (Flashcards)

A set of Question-and-Answer flashcards covering the key concepts from the provided lecture notes on forces, vectors, and motion.

What are the two broad categories of forces introduced in Chapter 1, and why does the direction of the vector matter?

Contact forces and action-at-a-distance forces; the direction of the vector matters because it determines the net effect on the object when forces are summed.

What symbol is used to denote the net force (the sum of all forces) acting on an object, and what is its origin?

The capital Greek letter Sigma (Σ); it represents the sum of all forces acting on the object.

How are vectors typically handled when analyzing forces on an object?

By resolving them into components along chosen axes (usually x and y) and then summing the components.

When dealing with motion on an incline, which direction is taken as the x-axis and why?

Along the incline (parallel to the surface) to simplify solving the problem to one-dimensional motion along the incline.

What is the unit of force, and what is the relation between weight, mass, and gravity?

The Newton (N); weight W = m g, where m is mass and g is gravitational acceleration (~9.8 m/s^2 on Earth).

Name three common types of forces discussed in these notes.

Tension, weight, normal force (also friction and spring/elastic/ restoring force are discussed as well).

What is tension and how is it typically represented in these notes?

The pulling force along a rope or cord; often represented by T or sometimes capital C.

What is the spring (elastic) force and what is it called?

The restoring force inside a spring that tends to return to equilibrium; called the elastic force or restoring force, proportional to the displacement (Hooke's Law F = -k x).

What is the normal force?

The perpendicular contact force exerted by a surface on an object, balancing perpendicular components of other forces.

What is a Free Body Diagram (FBD)?

A diagram that shows all external forces acting on an object depicted as vectors attached to the object.

What is an external force in Newton's laws, and how does it relate to acceleration?

A force exerted on the object by external agents (environment, other objects); the net external force Fnet determines the acceleration via Fnet = m a.

State Newton's first law as described in the notes.

An object moves with constant velocity (or remains at rest) if the net external force on it is zero.

What is a noninertial frame of reference, and why is it mentioned in this context?

A frame of reference that is accelerating; in such frames fictitious forces may appear in the analysis.

Why is it useful to align the x-axis with the incline in problems?

It simplifies the problem to one-dimensional motion along the incline and clarifies the force components along and perpendicular to the surface.

What does the symbol ΣF represent in physics problems?

The sum of all forces acting on the object (the net force).

What role does friction play in the discussion of forces?

Friction is a contact force that can act along a surface and must be included in free body diagrams when present.

How do you determine acceleration from forces?

Compute the net external force Fnet by summing all forces vectorially, then use a = Fnet / m.

What is the difference between mass and weight?

Mass is the amount of matter in an object; weight is the force due to gravity acting on that mass, W = m g.