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Monday, 20 October 2014

Why we need food

We all enjoy and eat food but why do we need it and what does our body do with it? Below are some of the main reasons why we need food.

For energy
You need food to work your muscles and other body organs. Food is the body’s fuel that keeps it going, without it the body would not work.

For growth and repair
In order for your body to grow you need to make new cells. New cells are also needed to replace old or damaged cells. Your body makes these new cells from the chemicals in your food.

To stay healthy
There are lots of reactions taking place in the cells of your body to keep you healthy and keep your body working. Certain chemicals are needed for these reactions which can only be taken in from the food you eat.

Moment

The turning effect of a force is known as the moment. It is the product of the force multiplied by the perpendicular distance from the line of action of the force to the pivot or point where the object will turn.

When undoing a nut fastened to a screw by hand one realises that the amount of force required is a lot greater than when undoing the same nut using a spanner. The spanner increases the distance between the fulcrum and the line of action of the force, thus for the same force a greater moment is obtained.

What are Enzymes?

Enzymes are proteins made up of long chains of amino acids. They control chemical reactions that take place in all living things such as digestion, respiration and photosynthesis. They are knows as Biological catalysts as they speed up chemical reactions allowing them to occur at a faster rate. During this process, however the enzymes themselves do not get used up and so can continue catalyzing the reaction.

Mensuration

Mensuration Formulas

Mensuration is the branch of mathematics which deals with the study of Geometric shapes, their area, volume and related parameters.

Some important mensuration formulas are:

1. Area of rectangle (A) = length(l) × Breath(b)

$A = l \times b$

2. Perimeter of a rectangle (P) = 2 × (Length(l) + Breath(b))

$P = 2 \times(l + b)$

3. Area of a square (A) = Length (l) × Length (l)

$A = l \times l$

4. Perimeter of a square (P) = 4 × Length (l)

$P = 4 \times l$

Life Processes

Biology is the study of living things. All living things are called organisms, both plants and animals are living organisms. But how we decide whether something is living or non-living depends on 7 life processes. If something is living it will carry out the 7 life processes below.

Forces and Motions

What are Forces?

A force results from the interaction between two objects. A force can be defined as a push or a pull which acts upon an object as a result of its interaction with another object.

When one object exerts a force on another object it always experiences an equal opposing force in return from the object it exerted the force on. Or in other words when two objects interact, the forces they exert on one another are equal and opposite. These forces are referred to as the action and reaction forces.