This page contains solutions to the NCERT Questions of class 9 Science book's chapter 1 "Exploration: Entering the World of Secondary Science"
Pause and Ponder
Q1. Think of a prediction you or your family made recently (for example, the outcome of a cricket match). Was it based on evidence and reasoning, or mainly on guesswork? How can scientific thinking improve such predictions?
Answer: Imagine you think a cricket team will win just because it is your favourite team. That is only a guess. Scientific thinking means looking at facts first. For example, you can check how the team played in recent matches, whether the players are performing well, and what the weather will be like. Using facts helps you make a better and smarter prediction.
Q2. Describe one situation where an approximate answer is good enough, and one where you would need a very exact value.
Answer: When you add salt to food, an approximate amount is usually fine because a little more or less does not make much difference. However, medicine must be measured very carefully. Even a small mistake in the amount can be harmful and may make a person sick.
Q3. Choose a real-life object (maybe a pressure cooker or a mobile phone) or a problem (maybe a traffic jam near your school). Make a sketch listing what kind of ideas from physics, chemistry, biology, earth science, or mathematics are involved. Show how at least two branches of science connect with your example.
Answer: A mobile phone uses different branches of science. Physics helps the phone send messages through invisible signals in the air. Chemistry helps the battery store and provide energy. The battery supplies power, and the phone uses that power to send messages and make calls. This shows how different sciences work together in everyday devices.
Ready to go Beyond
Question. How do Masks Work?
Answer: Masks help keep us safe from germs and viruses. To understand how a mask works, scientists use different types of science. Physics explains how tiny particles move in the air. Chemistry helps us understand the material of the mask. Biology tells us about viruses and germs. Mathematics helps scientists measure how well a mask can block them.