term 3 Flashcards
Types of force
Contact forces exist between objects that are touching each other.
Non-contact (field) forces exist between objects that are not in contact.
Effects of a force
Change motion – A force can cause an object at rest to begin moving. A force can also cause a moving object to stop. Forces can cause moving objects to speed up (accelerate) or slow down (decelerate).
Change direction – A force can cause a moving object to change direction.
Change shape – A force can deform an object.
When we measure the strength of a force, we measure it in a unit called?
newtons
Newton’s third law of motion
If object A exerts a force on object B, object B also exerts a force on object A. The forces will be equal in magnitude (strength), but opposite in direction.
Action reaction pairs
Two forces that are equal in magnitude, but act in opposite directions according to Newton’s third law.
Force is
a push or a pull. A force can cause motion, stop motion, change the direction of motion or change the shape of an object. Forces act in pairs and movement occurs when one of the two forces is stronger than the other.
define: cell
battery
conductors wires
the source of energy for the circuit
2+ cells
made of metal
define: fuze
bulb
buzzer
-a electrocal device that breaks the circuit when theres too much elctrical flow
-genrate heat and light
-converts electrical energy=sound energy
define: switch
resistor
motor
-A switch controls the flow of current
-device that resists the flow of current
-converts electrical energy=mechanical energy
define: conductor
insulator
free electrons
-A material that allows for the flow of current
-A material that doesn’t allow for the flow of current.
-electrons that are found in the atom’s outer shell
define: Electrical resistance
Imbalance of electrical charge
current
-Opposes the passage of electrons
-This is when some part of an object has a different amount of free electrons than another part
-The flow of electrons through a conductor
The Law of Conservation of electric charge
It means that you can never create a net electric charge. Instead, the charge can only move from one place to another.
Examples of: conductors
insulators
->Silver
Copper
Aluminium
Iron
Carbon
Water
->Plastic
Wood
Paper
Glass
Conventional current flows
from the positive terminal to the negative terminal of the cell.
The resistance of an object is defined as voltage over current
R=V/I
The Ohm Law states that:
The current flow through a conductor is directly proportional to the potential difference (voltage) and inversely proportional to the resistance.
define: LED
LDR
Ohm
Incandescent
Rheostat
-Light-emitting diode
-Light-dependent resistor
- The unit of measurement used for resistance
-Emit light as a result of energy.
-A resistor with variable resistance.
three field forces
Gravity
Magnetic force
Electrostatic force
Law of universal gravitation
any object with mass exerts an attractive force on all other objects with mass.
Gravity
A force that attracts all objects with mass towards the centre of another object that has mass.
define: Attraction
Repulsion
A force that pulls objects together.
A force that pushes objects away from each other.
field
A field is an area in space where certain objects experience a force, irrespective of what other objects they are in contact with.
weight
is the force by which the object is pulled down towards the centre of the Earth. Weight is a vector quantity as it has both magnitude and direction. Weight can be determined using a spring balance and it is measured in Newtons (N).
mass
is the amount of matter composing an object. Mass is a scalar quantity which means it has magnitude but no direction. We can measure mass using a simple scale and it is measured in grams (g) or kilograms (kg).
weight formula
W = m x g ‘m’, the mass of the object (in kilograms) by ‘g’, the gravitational force (in Newtons).
Planet or solar body
Earth
Moon
Mercury
Gravitational acceleration in the solar system.
9.8
1.625
3.61
Planet or solar body
Venus
Mars
Jupiter
Gravitational acceleration in the solar system
8.83
3.75
26
Planet or solar body Acceleration
Saturn
Uranus
Neptune
Pluto
Gravitational acceleration in the solar system
11.2
10.5
13.3
0.61
Explain the importance of magnetic fields
*Magnetic fields are crucial for Earth’s life, protecting it from cosmic radiation and charged particles from the Sun.
*They also serve as the basis for navigation using a compass and are essential for life on Earth.
When drawing magnetic field lines
The magnetic field line should always begin from the north pole and move towards the
south pole
magnets are ____ poles
dipoles south and north
magnetic field
A magnetic field is an invisible space around a magnetic object that describes the distribution of magnetic force around it
Articulate how lightning is an example of electrostatic forces.
Lightning is a natural phenomenon caused by electrostatic discharges between charged regions in the atmosphere, causing them to temporarily equalize when hitting an object on the ground.
