Forces, Magnetism, Electricity, and Energy

Comprehensive practice flashcards covering vocabulary, focus questions, and conceptual questions on forces, motion, magnetic interactions, electric circuits, electromagnets, motors, generators, and energy conservation.

What is a force?

A push or pull that causes motion.

What is friction, and how does it affect motion?

A type of force that resists motion; more friction creates more resistance to overcome.

What is required for a force to occur during an interaction?

Two or more objects must make contact.

What is kinetic energy?

Energy of motion.

What is the standard unit of measurement for force?

Newton.

What tool is used to measure force?

A spring scale.

What is net force, and what happens when it is zero?

Net force takes into account all forces acting on an object. If it is zero, there is no change in motion.

What type of forces make things move?

Unbalanced forces.

What is the relationship between the mass of an object and the force needed to slide it across a surface?

More mass requires more force.

Why do loads fail to move when only a small force is applied to one side?

The friction was too large to overcome.

What is gravitational force?

A pulling force bringing objects toward the center of the Earth.

What is a magnet, and what is a permanent magnet?

A magnet is an object that produces a magnetic field; a permanent magnet always has a magnetic field.

What is a magnetic pole?

The location where magnetic fields extend from.

How do like and opposite magnetic poles interact?

Opposite poles attract (pull together) and same poles repel (push apart).

What is induced magnetism?

Temporary magnetism that occurs when a magnet gives magnetic properties to an object that does not normally have them.

What is a magnetic field?

The area around a magnet where the magnetic force can be detected.

What tools or materials can be used to detect a magnetic field?

A compass or iron filings.

What common characteristic do all objects that stick to magnets share?

They are ferromagnetic, made of iron, nickel, or cobalt.

Can magnetism attract and repel through materials?

Yes, if the magnetic field is strong enough and the other object is ferromagnetic.

What happens to the force of attraction when more magnets are added?

The force of attraction increases.

Why does the magnetic attraction force increase significantly with a second magnet, but only a little with a third and fourth magnet?

The third and fourth magnets are farther away and exert less magnetic force.

What type of electrical current do D-Cell batteries supply?

Direct current.

What is required to complete an electric circuit?

Contact between components, power, and materials that conduct electricity.

What is an electric current?

The flow of electricity in a circuit.

How can you light a lightbulb using only one wire and a battery?

Make contact with the battery on one of the connection points of the lightbulb, and connect the wire to the other connection point.

What evidence indicates that an electric current is flowing through a wire if a compass is placed nearby?

A magnetic field exists around the current-carrying wire, causing the compass needle to react.

What is electromagnetism?

Using an electric current to induce magnetism in a core.

How does an electromagnet function, and how can its magnetic field be increased?

An electric current running through a wire generates a magnetic field around the wire; adding more wire creates a greater magnetic field.

In an electromagnet, what is the core?

The object that the wires are wrapped around.

What is insulation in an electrical circuit?

The plastic or rubber coating that prevents electricity from escaping the wire.

In an engineering context, what is the difference between a constraint and a criterion?

A constraint is a limitation, whereas a criterion is a necessary requirement.

What are the primary internal components of an electric motor identified in the notes?

Brush, commutator, shaft, and electromagnet.

How does an electric motor work to produce kinetic motion?

A battery provides power to an electromagnet on a shaft. Its polarity matches the polarity of permanent magnets in the casing, pushing the electromagnet away and causing the shaft to spin.

What energy transfer takes place inside an operating electric motor?

Electrical energy is converted into kinetic energy.

How does the function and energy transfer of a generator compare to that of an electric motor?

A generator produces electrical energy; its energy transfers are the exact opposite of an electric motor.

How do the internal components of a battery/motor system compare to those of a hand-crank generator?

They are basically the same; a generator contains a motor.

What happens when batteries are connected directly to a hand-crank generator?

The hand crank rotates and the lightbulb lights up.

What are examples of nonrenewable fossil fuels?

Oil, gas, and coal.

What is the difference between renewable and nonrenewable energy sources?

Renewable sources can be replenished, whereas nonrenewable sources cannot be replenished.

What is the Law of Conservation of Energy?

Energy cannot be created or destroyed; it can only be converted from one form of energy to another.