Introduction to Rockets

Introduction to Rockets- Launching using gas pressure

Introduction to rockets- Launching using chemical energy

Introduction to Rockets- Launching using mechanical pressure

Introduction to Rockets- Launching using exhaust pressure

Puzzle for Mammals

The following puzzle should help you learn the different types of mammals.
Reference: http://www.apples4theteacher.com/mammalws.html

Animal Cells

Animal cells are eukaryotic cells. They contain a cell membrane, nucleus, endoplasmic reticulum, microtubules, centrosomes, golgi apparatus, mitochondria, ribosomes, chromatin, and other organelles. However, animal cells do not contain cell wall, chloroplasts, and a large central vacoule like plants. Here are video and a picture that depict typical animal cells.

Water cyle

Average vs. Instantaneous Speed

During a typical trip to school, your car will undergo a series of changes in its speed. If you were to inspect the speedometer readings at regular intervals, you would notice that it changes often. The speedometer of a car reveals information about the instantaneous speed of your car. It shows your speed at a particular instant in time.

The instantaneous speed of an object is not to be confused with the average speed. Average speed is a measure of the distance traveled in a given period of time; it is sometimes referred to as the distance per time ratio. Suppose that during your trip to school, you traveled a distance of 5 miles and the trip lasted 0.2 hours (12 minutes). The average speed of your car could be determined as

On the average, your car was moving with a speed of 25 miles per hour. During your trip, there may have been times that you were stopped and other times that your speedometer was reading 50 miles per hour. Yet, on average, you were moving with a speed of 25 miles per hour.