Questions & Answers on Why do we fall ill? From the Exercise of NCERT Textbook for Class 9 Science Q 1. How many times did you fall ill in the last one year? What were the illnesses?(a) Think of one change you could make in your habits in order to avoid any of/ most of […]
Causes of Disease Disease may be caused due to several reasons like due to pathogens such as virus or bacteria; or due to internal factors such as genetic mutation; or even due to our negligence. We may classify the causes in various ways, e.g. 1. Immediate cause and Contributory cause. Immediate cause: The organisms that
Why do we fall ill – 2 (Cause & Prevention of Diseases) Read More »
Introduction Health and disease in human communities are very complex issues, with many interconnected causes. We also realise that the ideas of what ‘health’ and ‘disease’ mean are themselves very complicated. When we ask what causes diseases and how we prevent them, we have to begin by asking what these notions mean. We
1. Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’. (a) Suma is swimming in a pond. (b) A donkey is carrying a load on its back. (c) A wind-mill is lifting water from a well. (d) A green plant
Consider two children, say A and B. Let us say they weigh the same. Both start climbing up a rope separately. Both reach a height of 8 m. Let us say A takes 15 s while B takes 20 s to accomplish the task. What is the work done by each? The work done
According to this law, energy can only be converted from one form to another; it can neither be created nor destroyed. The total energy before and after the transformation remains the same. The law of conservation of energy is valid in all situations and for all kinds of transformations. The sum of kinetic energy
Law of Conservation of Energy – for CLASS 9TH (Physics) Read More »
Life is impossible without energy. The demand for energy is ever increasing. Where do we get energy from? The Sun is the biggest natural source of energy to us. Many of our energy sources are derived from the Sun. We can also get energy from the nuclei of atoms, the interior of the earth, and
Life is impossible without energy. The demand for energy is ever increasing. Where do we get energy from? The Sun is the biggest natural source of energy to us. Many of our energy sources are derived from the Sun. We can also get energy from the nuclei of atoms, the interior of the earth, and
