Title PHYSICS PART- 1.pdf ✅

PHYSICS Class - C4(Part - I) INDEX S.No Concept Topics Page Number 1. Wise Up 06 − 07 2. I. Quantity and types of quantities 07 − 10
3. II. Units and measurement of physical quantity 10 − 12 4. III. Fundamental units and rules for 12 − 16 w. IV. Multing units in S.I 6. V. Dimensions, Dimensional formula and 16 − 20 7. VI. Applications of Dimensional Method of Analysis 20 − 29 8. VII. Conversion of derived units 29 − 32 9. Additional Exercise 32 − 35 10. Quick Review 36 11. Analyse and assess 37 − 38 UNITS AND DIMENSIONS - IIWISE UP Science is what people know about the world and the life that is on it. The land, the ocean, the weather, the stars, the medicines, the plants and the animals are all the parts of science.
The word physics is taken from the Greek word physikos, meaning nature. However, it does not mean that all sciences which deal with nature are classified as physics. Broadly speaking, physics is a branch of science which deals with the study of matter and energy under various situations. Physics can be defined as the study of phenomena which are taking place in matter and energy. Length, Mass, Time are basic measurements. Length : Length is the measure of distance between two points. We can see that rod CD is longer than rod AB.
Mass : Mass is the amount of matter contained in a substance. Matter is made of molecules. In certain substances these molecules are more tightly packed, as compared to other substances. The total amount of matter of these molecules present in a given substance gives us the idea of mass. For finding the mass of substances in general, just as at grocer's shop a simplified form of physical balance. Time : Time is defined as a gap between two events. Solar day : The gap between two successive noons is called solar day. Mean solar day : The average of all solar days in which earth completes one revolution around the sun is called mean solar day. Area : The amount of surface occupied by an object or a place is called its area. Volume : The space occupied by a substance(solid, liquid or gas) is called volume. Density : The mass per unit volume of a substance is called density. Imagine that you have an aluminium cube of volume 20 cm3 . If it is weighed on physical balance, then its mass is 54 g. Now we can say . 20 cm3 of aluminium has mass = 54 g ∴ 1 cm3 of aluminium has mass = 54 g 20 cm3 = 2.7 g cm3 or 2.7 g cm−3 As the mass per unit volume is the density.