Physics Concepts and Principles

A comprehensive set of flashcards covering the concepts discussed in the lecture notes on physics, forces, energy, electricity, and machines.

What is a force?

A force is a push or a pull that can change the speed, direction, size, or shape of an object.

How is force measured?

Forces are measured using a force meter or a newton meter, and the unit of measurement is the newton (N).

What do Newton's first laws state?

An object at rest will stay at rest or continue moving in a straight line at a constant speed unless acted upon by an unbalanced force.

What does the second law of motion concern?

The second law of motion is concerned with acceleration, which is the rate at which speed changes when a force is applied.

What is Newton's third law of motion?

For every action, there is an equal and opposite reaction.

What is a resultant force?

A resultant force is the combined effect of more than one force acting on an object at the same time.

How is resultant force determined?

If two forces act in the same direction, the resultant force is the sum of the forces; if they act in opposite directions, the resultant force is the difference between them.

What is friction?

Friction is a force that acts against the direction of movement when two objects are touching each other and one moves against the other.

What is air resistance?

Air resistance is friction caused by air when an object moves through it.

What produces lift in birds and airplanes?

Lift is produced by the shape of their wings, with an aerofoil shape changing the airflow.

What is gravitational force?

Gravitational force exists between any objects with mass; the greater their mass, the greater the attraction.

What is the center of gravity?

The center of gravity is the position through which gravitational force acts.

How does the position of the center of mass affect stability?

The position of the center of mass in relation to its base determines the stability of an object.

What is centripetal force?

Centripetal force is the force acting on an object moving in a circular path, always directed towards the center of the circle.

What is centrifugal force?

Centrifugal force is an equal and opposite force to centripetal force, acting away from the center of circular motion.

What is a moment in physics?

A moment is defined by the size of the force and the distance from the force to the pivot point.

What does the law of moments state?

In equilibrium, the anticlockwise moment must equal the clockwise moment.

What is energy?

Energy is the ability to do work.

What is kinetic energy?

Kinetic energy is the energy an object has when it is moving.

What is potential energy?

Potential energy is stored energy that can be released to do work.

What does the law of conservation of energy state?

Energy is neither created nor destroyed but can be converted from one form to another.

What are the two types of collisions?

Inelastic and elastic collisions.

What are good conductors of electricity?

Good conductors, like copper and graphite, allow electric current to flow easily.

What is resistance?

Resistance is the opposition to current flow, measured in ohms (Ω).

What does V = IR represent?

V = IR represents the relationship between voltage (V), current (I), and resistance (R).

What is direct current (d.c.)?

Direct current (d.c.) travels in only one direction around a circuit.

What is alternating current (a.c.)?

Alternating current (a.c.) can flow in one direction and then in the opposite direction.

What is the purpose of a fuse?

A fuse is designed to melt if a current larger than a certain value passes through it, protecting the circuit.

What is mechanical advantage?

Mechanical advantage is the ratio of the load to the effort in a machine.

What is a single fixed pulley?

A single fixed pulley does not multiply force but can change the direction of the applied effort.

What is a lever?

A lever is a machine that rotates about a pivot point, used to move a load with force called effort.

What are renewable energy sources?

Renewable energy sources, like solar and wind energy, are continuously replaced as they are used.

What is a screw in physics?

A screw is an inclined plane that allows for the load to be moved a distance equal to its pitch.

What is the importance of maintaining machines?

Machines must be maintained to prevent rusting and ensure efficiency.

What is the role of solar panels?

Solar panels absorb heat energy from the sun and convert it into electricity.

What can be used to protect electrical devices from faults?

Earth leakage circuit breakers can switch off the current quickly if a fault occurs.

What are curved mirrors used for?

Curved mirrors reflect light and can be used in car headlamps, rear-view mirrors, and satellite dishes.

What produces a magnetic field?

A current flowing through a wire produces a magnetic field.

How does an electromagnet work?

An electromagnet consists of a coil of wire around a soft iron core, becoming magnetized when current flows through it.

What is the unit for power?

The unit for power is the watt (W).

What is work in physics?

Work is done when a force is applied to an object and the object moves in the direction of the force.

What is power in the context of work?

Power is the rate at which work is done, calculated as work done divided by the time taken.

What is the formula for calculating work?

Work (W) is calculated using the formula W = F × d, where F is force and d is distance.

What is energy transfer?

Energy transfer is the process of transferring energy from one object or system to another.

What is thermal energy?

Thermal energy is the internal energy present in a system due to its temperature.

What is electrical energy?

Electrical energy is the energy carried by electric charge, which can be used to do work.

What is nuclear energy?

Nuclear energy is the energy released during nuclear fission or fusion.

What are fossil fuels?

Fossil fuels are natural substances formed from ancient organic matter, used as energy sources, such as coal, oil, and natural gas.

What is potential energy in a gravitational field?

Gravitational potential energy is the energy stored in an object due to its height above ground, calculated as PE = mgh, where m is mass, g is gravitational pull, and h is height.

What does a circuit diagram represent?

A circuit diagram is a visual representation of an electrical circuit using standard symbols for components.

What is an insulator?

An insulator is a material that does not allow electric current to flow through it easily.

What is a conductor?

A conductor is a material that allows electric current to flow through it with minimal resistance.