81 - 90 van 97 bronnen weergeven

Scale of cells

Even though molecules, proteins, viruses, and cells are all tiny, there are significant size differences between them. The diameter of a water molecule is roughly 0.28 nanometers. The diameter of the protein hemoglobin is roughly 5 nanometers. The diameter of the HIV virus is roughly 120 nanometers. A red blood cell is 6-8 micrometers.

Onderwerp en thema
Form 1
Biology
Cell structure and organisation
Concept of cells
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2015
Schepper/Auteur
Sal Khan
Trefwoord
Cells

Simple Machines

In this lesson you will learn about:

  • Simple machines
  • Be able to identify different kinds of machines
  • Identify classes of levers and pulleys
  • Determine mechanical advantage of a lever and pulleys
  • Understand and determine the advantage of an inclined plane
  • Describe and determine the advantage of a screw jack
  • Describe and determine the advantage of a wheel and axel
  • Describe and determine the advantage of a hydraulic press

 

 

Onderwerp en thema
Form 2
Physics
Simple machines
Type bron
Cursus
Taal
English
Publicatiedatum
2023

Simple Machines

What are simple machines? Simple machines are tools that make work easier. They have few or no moving parts. These machines use energy to do work with one movement. They make our work easier by letting us use less mechanical effort to move an object.

Onderwerp en thema
Form 2
Physics
Simple machines
Concept of simple machines
Type bron
Studieboeken
Taal
English
Uitgever
Department of Higher Education
Publicatiedatum
No date
Schepper/Auteur
Leigh Kleynhans
Deelnemer
Michael Atkinson
Trefwoord
Lever
Pulley
Inclined plane
Wedge

Skeletal structure and function

Skeletons support and protect our bodies. Bugs have exoskeletons outside their bodies, while humans have endoskeletons inside. Our bones are in axial (skull, ribcage, spine) and appendicular (arms, legs) groups. Bone marrow makes blood cells; more specifically, red marrow makes blood and yellow marrow stores fat. 

Onderwerp en thema
Form 1
Biology
Introduction to biology
Concept and terminologies of biology
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2014
Schepper/Auteur
Tracy Kim Kovach
Trefwoord
Skeletal structure

Space station speed in orbit

Speed necessary for the space station to stay in orbit.

Onderwerp en thema
Form 2
Physics
Motion in a straight line
Motion under gravity
Type bron
Video
Taal
English
Uitgever
Khan Academy
Publicatiedatum
2011
Schepper/Auteur
Sal Khan
Trefwoord
Speed
Gravity
Law of Universal Gravitation

Static Electricity

Electric charge comes in two varieties, which we call positive and negative. Like charges repel each other, and unlike charges attract each other. Thus, two positive charges repel each other, as do two negative charges. A positive charge and a negative charge attract each other.

How do we know there are two types of electric charge? When various materials are rubbed together in controlled ways, certain combinations of materials always result in a net charge of one type on one material and a net charge of the opposite type on the other material. By convention, we call one type of charge positive and the other type negative.

Onderwerp en thema
Form 2
Physics
Static electricity
Concept of static electricity
Type bron
Studieboeken
Taal
English
Uitgever
openstax
Publicatiedatum
2020
Schepper/Auteur
Openstax
Trefwoord
Conduction
Conductor
Electron
Induction
Proton

Static Electricity

In this lesson you will learn that:

  • Static electricity is a build-up of charge in an object.
  • The build-up pf charge is caused by insulating materials rub against each other.
  • The motion of these charges causes small shocks, lightening and sparks.
  • These charges can be detected. 
  • Certain materials can be classified as insulators, and others as conductors.
  • Capacitors are small devices in circuits which can store charge.
  • Lightning rods are used to allow charges from strikes to travel safely and dissipate in the Earth
Onderwerp en thema
Form 2
Physics
Static electricity
Type bron
Cursus
Taal
English
Publicatiedatum
2023

Sura za Meiosisi - Phases of Meiosis

The phases of Meiosis.

Onderwerp en thema
Form 1
Biology
Introduction to biology
Scientific processes in biology
Type bron
Video
Taal
English
Uitgever
KhanAcademyKiswahili
Publicatiedatum
2012
Schepper/Auteur
KhanAcademyKiswahili
Trefwoord
Meiosis

Temperature

In this unit you will: 

  • Understand that temperature is a measure of average kinetic energy.
  • Learn about the various temperature scales that are commonly used in science.
  • Learn to read temperature scales.
  • Differentiate between various thermometers (alcohol or mercury-based).
  • Understand that physical properties change when there is a change of temperature.

 

 

Onderwerp en thema
Form 2
Physics
Temperature
Type bron
Cursus
Taal
English
Publicatiedatum
2023