Archive | Question and Answers

Energy is all around us. Energy can neither be created nor destroyed. This is called the law of conservation of energy.

We use energy to do work. When we play for a long time we feel tired, and our ability to work is reduced.

The force acting per unit area on a surface is called pressure. Pressure can be exerted on an object by:

A push or a pull on an object is called a force. A force causes motion. For example, we lift, push or pull a book lying on a table, kick a football, hit a cricket ball with a bit…

When a body changes its position, it covers some distance within a certain time. To find the speed of a body we divide the distance covered by time taken.

When we walk on a road remove from one position to another. It means that we are in motion.

Various types of thermometers have been designed to measure temperature. Two of the commonly used thermometers are:

Organ systems in our body cannot functions independently. They have to work hand-in-hand (in coordination with) with other organ systems.

You must have used an umbrella on a rainy day. It has a metal frame with many spokes which gives the umbrella its shape.

The muscular system is responsible for all kinds of movements in the body. All living organisms can move either their whole body from one place to another or some body part.

Reproduction is an important characteristic of living organisms. It is the process by which an individual produces young ones of its own kind.

Excretion is the elimination of waste products from the body. The breakdown of different chemical substances in the body to release energy produces many waste products.

All animals react to changing condition in the environment. In the human body several organs and organ systems perform numerous actions in association with each other.

All parts of the body require nourishment and oxygen. At the same time waste products need to be removed from all the cells in the body.

All the cells in our body require energy to carry out diverse functions. The energy comes from the food we eat.

The digestive system includes the organ concerned with the intake of food, its digestion and absorption.