Physics Gr11 Definitions

Scalar

Physical quantity with a magnitude

Vector

Physical quantity with a magnitude and direction

Resultant vector

Single vector that has the combined effect of 2/+ vectors acting together

When is a system an equilibrium?

When the resultant vector =0

Normal force

Contact force exerted by a surface that it is perpendicular to the surface.

Friction

Contact force opposing the motion of an object and acts parallel to the surface.

Static friction

Contact force that opposes the tendency of motion of a stationary object and acts parallel to the surface.

Kinetic friction

A contact force that opposes the motion of a moving object and acts parallel to the surface.

When does static friction reach a maximum

When the object is about to move

Which coefficient is bigger between static friction and kinetic friction?

Static friction

Field

A region of space in which an object experiences a force.

What is the relationship between maximum static friction and normal force?

Directly proportional

Stating that an object is in a vacuum means

There is no friction force and normal force. The object is not on a surface.

Newton’s first law of motion

An object will remain in a state of rest or motion at a constant velocity unless a non-zero resultant force acts on it.

Inertia

The resistance of an object to change its state of motion or rest

Mass

Measure of how much matter is in an object.

A measure if an object’s inertia.

Relationship between mass and inertia

Directly proportional.

Newton’s second law of motion

When a net force is applied to an object, the object will accelerate in the direction of the net force with an acceleration that is directly proportional to the net force and inversely proportional to the mass of the object.

Relationship between net force and acceleration.

Directly proportional.

Newton’s third law of motion

When 1 body exerts a force on a second body, the second body SIMULTANEOUSLY exerts a force of equal magnitude in the opposite direction on the first body.

Pick one example of Newton’s third law.

Weight

Measure of gravitational attraction force of earth on an object.

Newton’s law of universal gravitation

Every body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

What does gravitational acceleration depend on?

• Earth’s mass

• Distance from centre of the earth

• NOT mass of object

In Galileo’s famous experiment when we ignore air resistance…

Fnet=W

ma=mg

a=g

Energy

A scalar measured in joules

Gravitational potential energy

The energy that an object has due to its position in a gravitational field relative to a reference point.

Potential energy

Stored energy.

Types of potential energy

• Chemical potential energy

• Elastic potential energy

• Gravitational potential energy

Where is a gravitational field found?

Around all matter

Kinetic energy

The energy an object has as a result of its motion.

How does kinetic energy increase?

When an object moves faster

Mechanical energy

The sum of the gravitational potential energy and kinetic energy in a system.

The Law of Conservation of Energy

Energy cannot be created or destroyed. It can only be transformed from one form into another.

When does the total mechanical energy in a system remain constant?

When the system is isolated.

When will we be able to draw a closed vector diagram?

When the system is an equilibrium.

Law of Conservation of Charge

The net charge of an isolated system remains constant during any physical process

Electrostatic Force

Force between charges

Coulomb’s Law

The magnitude of the electrostatic force exerted by one point charge on another point charge is directly proportional to the products of the magnitudes of the charges and inversely proportional to the square of the distance between them.

Electric field

A region where an electric charge experiences a force.

Electric field at a point

The electrostatic force experienced per unit positive charge placed at that point.

Faraday’s Law

The induced EMF in a circuit is directly proportional to the rate of change of magnetic flux through the circuit.

Potential difference

Amount of energy transferred per charge when it moves from one point to another.

EMF

The total amount of energy supplied by a battery per unit charge.

Total EMF

Voltage used in battery and voltage supplied to circuit.

Electric current

Rate of flow of charge

Conventional current

Direction of current from positive to negative

Resistor

Opposition of the flow of current

Ohm’s Law

The voltage in a conductor is directly proportional to the current through it at a constant temperature.

Power

Rate of work done