how do desert plants survive? (adaptations)

desert plant adaptations:

- reacts rapidly when sufficient rain falls
eg. seeds can germinate, grow up into plants, flower, and repeat the cycle all over again in just 2 weeks. these flowers are called "ephemerals".

- colourful petals
ephemerals have colourful petals to attract desert insects.
-some plants are coated in a certain chemical

- the plants are coated in the chemical in order to prevent them from germinating, until the rain washes the chemical away.

- have shallow widespread root systems
desert succulents (eg. cacti) have such a root system to absorb large amounts of rainwater quickly. This can be stored in the stems of the cacti , some of which are ribbed in order to permit expansion.

- spines on stems
the spines on the stems are to prevent desert animals from taking the stored water.

- cacti takes in carbon dioxide at night and stores it in other chemical compounds.
the stomata are open to allow gaseous exchange when the air is coo, resulting in water loss kept to a minimum. the carbon dioxide is then released and used during photosynthesis.

- a certain species of daisies grows in the desert.

Title of book: eyewitness science-Ecology
Author: Steve Pollock

-smaller leaves

-grow compactly to the ground

-non-porous covering on leaves (eg. wax)

hair on the leaves of the desert plants helps to reduce the evaporation of moisture from the surface of the leaves by reflecting sunlight and inhibiting air movement.

-adapted root system

some plants (phreatophytes) have adapted root systems long enough to reach underground water sources.

-some plants (perennials) survive by becoming dormant during dry periods, then springing to life when water becomes available (eg. ocotillo)

-the leaves of certain plants face directly down or up (eg. spines or fur tree)

the leaves are faced this way so that the amount of heat is reduced resulting in less water evaporating.

-some plants only expose a few of their leaves, most of them are underground along with the main body. (eg. living stones)

this is done so that the plant does not loose all it's water to the sun, the trees are also kept cooler.

bullet train.

since everyone is posting about airplanes, i shall post about a train. (:

The Shinkansen (新幹線^?, new main line), also known as the bullet train, is a network of high-speed railway lines in Japan operated by four Japan Railways Groupcompanies. Starting with the 210 km/h (130 mph) Tōkaidō Shinkansen in 1964, the now 2,459 km (1,528 mi) long network has expanded to link most major cities on the islands of Honshū and Kyūshū at speeds up to 300 km/h (186 mph). Test runs have reached 443 km/h (275 mph) for conventional rail in 1996, and up to a world record581 km/h (361 mph) for maglev trainsets in 2003.

Shinkansen literally means new trunk line, referring to the tracks, but the name is widely used inside and outside Japan to refer to the trains as well as the system as a whole. The name Superexpress (超特急 chō-tokkyū^?), initially used for Hikaritrains, was retired in 1972 but is still used in English-language announcements and signage.

The Tōkaidō Shinkansen is the world's busiest high-speed rail line. Carrying 151 million passengers a year (March 2008), it has transported more passengers (over 6 billion) than any other high speed line in the world. Between Tokyo and Osaka, the two largest metropolises in Japan, up to ten trains per hour with 16 cars each (1,300 seats capacity) run in each direction with a minimum of 3 minutes between trains. Though largely a long-distance transport system, the Shinkansen also serves commuters who travel to work in metropolitan areas from outlying cities.

website:http://en.wikipedia.org/wiki/Shinkansen

how high can you jump and how long can you stay in the air?

But is jumping really flying? Yes and no. Some things like rockets, cannonballs, and baseballs fly like jumping kids_they are pushed into the air by engines or muscles. But what about airplanes? It's true they are pushed forward by engines, but air is what pushes and holds them up. Thrust, drag, weight, and lift are the four forces that usually work together to make things fly. You already know something about each of them, although you might not have called them by their names. If you thought that having stronger muscles or springy shoes or a rocket booster might help your jump, then you were thinking about thrust (the "muscle" that pushes you during flight). If you thought that a slick suit or helmet would make you jump higher or that a parachute would keep you in the air longer, then you were thinking about drag (the way air tends to slow things that fly). Obviously weight is important - if you could lose weight by changing clothes, dieting, or visiting the Moon, you would probably jump higher Most people have experienced how thrust, drag, and weight can help them jump higher or "fly," but few people are familiar withlift. Lift is a push that comes from the air. You were thinking about this force if you decided that wearing wings or holding helium balloons would help you jump higher. Planes and birds have to be moving to get enough of this push to fly; hot-air balloons are light enough for their size that the air will lift them up whether or not the balloon is moving. You may want to find out more about this key force to better understand how things fly. Does everything that flies use all four forces? Nope. Only two forces - weight and thrust - help spacecraft fly. Lift and drag won't help spacecraft flying in space, where no air exists. This was a quick overview of the forces of flight. Don't stop here, though - look for more information about how high you can fly. website:http://www.nasm.si.edu/exhibitions/gal109/lessons/text/look.htm

if you jump up on a moving bus, will you land on the same spot?

You will land in the same place relative to that vehicle, provided that vehicle is going at a constant speed in a constant direction.

You can try this on a train. Make sure you try it when the train is not speeding up, slowing down, or going around a corner. Jump as high as you can, and you should land in basically the same spot on the floor of the train. But if you do it while looking out the window, you will see that you are still passing objects.

This is because of inertia, described by Newton's first law.

"An object in motion will remain in motion unless acted upon by a net force."

So with no wind inside the train, and no-one pushing on you, you will land on the same spot on the floor of the train from which you jumped.

Source: http://en.wikipedia.org/wiki/Law_of_inertia

website:http://wiki.answers.com/Q/If_you_jump_up_and_down_in_a_moving_vehicle_will_you_land_in_the_same_spot_and_why

MEDICINE BALLS.

(this may seem like a really random topic, but i used a medicine ball in netball training yesterday.)

DEFINITION:

A medicine ball (also known as an exercise ball, a med ball, or a fitness ball) is a weightedball roughly the diameter of the shoulders (approx. 14 inches). Often used for rehabilitation andstrength training, it serves an important role in the field of sports medicine. It should not be confused with the larger, inflated exercise ball.

CONSTRUCTION:

medicine balls are generally constructed of a leather or vinyl covered nylon cloth, and filled with impact absorbing materials to give them weight. Vinyl covered medicine balls typically are sand filled and are not used for exercises requiring bouncing. Sand or steel shot filled neoprene bags are also used for medicine ball exercises not requiring bouncing.

Some medicine balls have an inner half sphere of dense material in varying thicknesses and seamed together with an outer rubber shell. Other medicine balls have a thin rubber bladdercovered by a thick rubber outer surface. Medicine balls that are constructed with an inner rubber bladder and rubber outer surface incorporate an air valve to pump up the ball and increase the bounce. The outer rubber surface has indented designs for easy handling. Over time the rubber surface may wear down if the medicine ball has been used on rough surfaces.

Other types of medicine ball include balls made of gel-filled polyvinyl chloride shells, balls made of solid polyurethane, and neoprene bags filled with sand or steel shot. The materials can vary depending on the desired weight and density.

A basketball can be filled with sand, stitched shut, and used as an effective low-price medicine ball where resources are scarce, and is popular in, for example, home "garage" gymnasia.

reflections/ summary for term 2 (:

Physics lessons this term were awesome. they were interesting, yet educational. (: something interesting i learnt this term is that face blotters actually aren't good at all. i had no idea that when you wipe your face with it, your face becomes drier, and results in your face producing more oil! also, i feel that all the videos we watched were interesting and helped me understand the concept of each topic better. an example would be the home alone video helped me understand forces better.

Last but not least, i feel that ESP is a great program and i would love to continue being in it.

LEVERS.

Class 1: the fulcrum is located between the applied force and the load. Example: the crowbar.

Class 2: the load is situated between the fulcrum and the force. Example: the wheelbarrow.

Class 3: the force is applied between the fulcrum and the load. Example: the human elbow joint on flexion.