This science curriculum article investigates the three main forces of drag- namely aerodynamic drag, hydrodynamic drag and frictional drag. This article considers the following: reasons why objects in forward motion slow down; effects of aerodynamic drag on cyclists and formula 1 racing cars; evolution of underwater predators with streamlined shapes; how dolphins have evolved to reduce skin drag by shedding their skin as they swim through water.
An explanation of how an astronaut’s mass would remains constant no matter what planet he visits in our solar system. An exploration of how weight would change on different planets as a result of differing forces of gravitational attraction. How measuring your weight actually measures the force of gravitational attraction between you and the planet you are visiting. A Homer Simpson story invented about how he would like to lose weight by becoming an astronaut.
This science teaching resource considers the issue of ‘weightlessness’ and addresses the common misconception that ‘weightlessness’ means there can be little or no gravity in space.The reasons why astronauts appear to ‘float’ in space are explained; rockets need to reach high velocities in orbit and the spherical shape of the Earth means that the surface of the Earth is forever disappearing. ‘Escape speeds’ are also discussed.
A science project which introduces the force of gravity. Students are introduced to the meaning of ‘mass’ and it is explained how we need to understand ‘mass’ before can understand ‘gravity’. Gravity is discussed with reference to Planet Earth, the Moon and the Solar System. We look at examples of gravitational forces and how the forces of gravity affect our everyday lives. We discuus the gravitational force the Sun exerts on the planets in our Solar System.
This school science resource considers the reasons behind the taming of wolves in prehistoric times which preceded the evolution of the domestic dog. We investigate plausible theories explaining how wolves first became tamed through processes of both ‘artificial’ and ‘natural’ selection.We then take a look at the exciting project started in the 1950′s by a Russian biologist which successfully bred tame foxes from wild foxes within only a few generations.
In this school science article we look at ‘evolution by artificial selection’; that is,how human activity has shaped and sculptured the physical appearance of certain organisms. We briefly look at the evolution through artificial means of fancy pigeons, cows, dogs, wild cabbage and (perhaps!) a certain crab. We are introduced to Charles Darwin for the first time and the contents of the first chapter of his book ‘On the Origin of the Species through Natural Selection’.
This school science article looks at the evolution of the ‘beach mouse’, a subspecies of the ‘Oldfield’ mouse, which inhabits barrier islands in Florida and Alabama. The article examines the evolutionary pressures 6000 years ago which led to Beach mice evolving light coloured coats and discusses the issues that arise within the context of ‘evolution by natural selection’. ‘Random mutations’ are discussed as are ‘good’ and ‘bad’ genes.
The evolutionary development of the elephant seal from its distant ancestor, the Puijila darwini which lived in the Canadian Arctic 25 million years ago; the evolutionary pressures which led to descendants of the Puijila adapting and changing to form new species;how intermediate ancestors became less ‘Puijila like’ to more ‘elephant seal like’; the adaptions which make the elephant seal an amazing hunter in the deep oceans; sexual dimorphism in elephant seals.
An introduction to ‘evolution by natural selection’; examples of organisms that are equipped to survive in their natural habitats; animals that have evolved over time; how a peacock’s impressive plumage has evolved to help them reproduce; a brief explanation of how organisms are programmed to behave in certain ways; the role of DNA in natural selection;a definiton of ‘evolution by natural selection’; the vast timescale over which evolution can take place.
This school science article is suitable for Year 3/Grade 2 students. We understand how pollen can be carried by the wind from male pine cones to fertilise the female pine cones of other pine trees; we learn how wind borne pollen fertilises some types of plants and that the flowers of such plants are not attractive to insects; we look at the pollination of grasses and how lawns can spread through underground roots; we take a brief look at the pollination of sea grasses.