Area – The space occupied (enclosed by the sides or surface) by an object is called the area or surface area. We have formulas To calculate the area of various shapes : Area of a square = side x side Area of a rectangle = length x breadth Area of a triangle = 𝐴= 1 2 𝑥 𝑏𝑎𝑠𝑒 𝑥 ℎ𝑒𝑖𝑔ℎ𝑡 What is the area of a square with sides measuring 6 cm. Area of a square = side x side 6cm 6 cm 6 cm 6cm

Calculate the area of a geometry box of length = 20 cm and breadth = 7 cm. Area of a rectangle = length x breadth 20 cm 7 cm Find the area of a right angled triangle with base = 9 cm and height = 4 cm. 4 cm 9 cm

S.I. unit of length is metre and Standard unit for Area is 𝑚𝑒𝑡𝑟𝑒 2 Multiple or Larger Units 𝑘𝑖𝑙𝑜𝑚𝑒𝑡𝑟𝑒 2 1 𝑘𝑚 2 = 1 km x 1 km = 1000 m x 1000 m = 10 3 𝑚 x 10 3 𝑚 = 10 6 𝑚 2 1 acre = 4046.85 𝑚 2 1 hectare = 2.471 acres Submultiple or Smaller Units 𝑐𝑒𝑛𝑡𝑖𝑚𝑒𝑡𝑟𝑒 2 1 𝑐𝑚 2 = 1 cm x 1 cm = 10 𝑚𝑚 x 10 𝑚𝑚 = 100 m 𝑚 2 = 10 2 𝑚 𝑚 2

http://www.youtube.com/watch?v=x0NHC0cmKfU How to calculate area of an irregular surface?

DAY – ONE QB 1,2,5,7,8,9 in note book (CW) QC 13,15,16 in note book (CW). Home work for Physics Textual Exercise QA (1,2,3,4) in text book (HW) QB 4 same as 6 (in text book) QC 10,11,12 in text book (HW)

The amount of matter contained in a object is the measure of its mass. A type of balance is used to measure the mass Smaller units of mass g and mg Larger units of mass quintal and metric ton 1000 mg = 1 g 1000 g = 1 kg 100 kg = 1 quintal 10 quintals = 1 metric ton

The space occupied by an object is known as its volume or capacity. Sub-multiple Unit of Volume S.I. Unit of Volume is 𝑚𝑒𝑡𝑟𝑒 3 . 𝑐 𝑚 3 is the smaller unit. 1 𝑚 3 = 1 m x 1 m x 1 m = 100 cm x 100 cm x 100cm = 1000000 𝑐𝑚 3 or 10 6 𝑐𝑚 3 1𝑐𝑚 3 = 10 −6 𝑚 3 1𝑑𝑚 3 = 10 −3 𝑚 3 1𝑐𝑚 3 = 10 3 𝑚𝑚 3 We have formulas To calculate the volumes of various solids : Volume of a cube = 𝑙 3 Volume of a cuboid = l x b x h Volume of a sphere = 4 3 𝜋 𝑟 3 Volume of a cylinder = 𝜋 𝑟 2 ℎ 10 Raised to the power 3

The inner volume of a container is expressed as its capacity The inner volume of a container is expressed as its capacity. The volume of liquid is expressed in litre (L)

http://www.youtube.com/watch?v=n3ia4i-uFTM Measuring of volume using displacement

How much is 1 litre of liquid in cubic centimetre How much is 1 litre of liquid in cubic centimetre? We know that each side of a 1 litre of square container is 10 cm. Hence 1 litre = Volume of square of 10 cm = 10 cm x 10cm x 10 cm = 1 dm x 1 dm x 1 dm = 1 𝑑𝑚 3 or 10 3 𝑐𝑚 3 Sub-multiple unit of litre is millilitre (mL) 1 litre = 1000 ml 1 mL is same as 1 1 𝑚 3 =1000 𝐿 side cc

DAY – ONE QB 1,2,5,7,8,9 in note book (CW) QC 13,15,16 in note book (CW). Home work for Physics Textual Exercise QA (1,2,3,4) in text book (HW) QB 4 same as 6 (in text book) QC 10,11,12 in text book (HW)

1B. Measurement of Time, Temperature and Approximation Definition : The interval between two instances or events is called time. Start End 1 ½ hour = time interval How is time interval = 1 ½ hour found? By measuring it

Time is measured with the help of or by using the time taken by earth to complete one rotation about its own axis which is also known as the mean solar day. S.I. unit of time is seconds or s in short Other units 60 seconds = 1 minute 60 minutes = 1 hour 24 hours = 1 day (is the time taken to complete 1 mean solar day) 365 days = 1 year. 10 years = 1 decade 10 decade = 1 century 10 centuries = 1 millenium

Devices to tell time – Clocks 1. Sundials They were used to record time during the days of Alexander the Great (300 B.C.) Based on the fact that shadow of an object changes its position an length with the position of sun in the sky.

2. Pendulum clock They measure time by making use of time taken by a pendulum for each oscillation A simple pendulum consist of a heavy point mass suspended on a rigid support by a massless, and inextensible string. Mean position, extreme position and oscillation

Devices to measure time intervals – STOPCLOCKS 1 Devices to measure time intervals – STOPCLOCKS 1. Stop clocks or stop watch 2. Electronic stop watch Accuracy upto 1 second Accuracy upto 0.01 second measuring timings in athletic activities. 3. Atomic watches used in scientific works can record up to 10 millionth of a second Ques. In a 24 hour clock what is a.m. And p.m.?

DAY 2 TEXTUAL EXERCISE

Cylindrical bulb filled or containing mercury or alcohol. Temperature Definition : Temperature is the measure of the degree of hotness or coldness of a body or environment. S.I. unit is kelvin. Commonly used unit is degree celsius and degree Fahrenheit . Instrument : Thermometer. Cylindrical bulb filled or containing mercury or alcohol. Bulb is attached to a cylindrical glass tube called capillary tube. The outer body is triangular in shape which magnify the readings on the body. The markings are calibrated in degrees.

Melting point and boiling point of water is taken as a reference for calibration as the lower and upper fixed points. Fahrenheit Celsius Kelvin 32⁰F 0⁰C 273⁰K 212⁰F 100⁰C 373⁰K Unit size is calculated by using the equation or formula C/5 = (F-32)/9 180⁰ F = 100⁰ C Unit size is 1⁰C (named after Swedish scientist Anders Celsius called centigrade as there are 100 degrees between lfp and ufp Lowest possible temperature is 273⁰ below freezing point of water Unit size is same as celsius scale ⁰K = ⁰C + 273

Types of Thermometers 1. Laboratory thermometer has markings between -10⁰C to 110⁰C. Each division is of 1⁰C. Used to measure temperature of other body 2A. Clinical thermometer has markings between 35⁰C and 42⁰ (human body temp. range, normal body temp is 37.8⁰C. A constriction in the capillary tube near the bulb checks the backflow of mercury to record the temperature of patient when it is taken out of the mouth. 2B. Nowadays digital thermometers that do not use mercury are used by doctors as it is difficult to dispose mercury which is toxic in nature.

Maximum ,minimum temperatures attained during a day is found using Six’s thermometer Inventor was Sir James Six (1782) Used in meterology and horticulture It measures the temperature by the expansion and contraction of the liquid

Gives two temperature readings maximum and minimum Gives two temperature readings maximum and minimum. U tube with two bulbs fitted at the top of each arm. Bulb A at the top of minimum reading scale contains alcohol Bulb B contains vacuum or low pressure alcohol vapour As temperature rises, Alcohol in bulb A expands and pushes the mercury lying below it, which results in the rise if mercury into the other arm. We can read the corresponding high temperature on the scale below bulb B. When temperature drops or falls, Alcohol in bulb A contract causing mercury below it to move towards bulb A and we can thus read the corresponding low temperature on the scale below bulb A. Two steel barbell-shaped marker inside the tubes record the farthest points reached by mercury in both the arms The markers can be reset by dragging them back on the surface of mercury using a magnet.

Advantages of using mercury in thermometer Advantages of using mercury in thermometer. Opaque and shiny liquid – easily visible Does not wet glass Used over wide range of temperature (f.p. -39⁰C b.p.357⁰C) Good conductor of heat – expands quickly Wide range of temperature expansion (temperature interval is wide)

DAY 3 TEXTUAL EXERCISE

Approximation or estimation – quick judgment about any measurement Approximation or estimation – quick judgment about any measurement. Useful when rough measurements are required. Used by Mother – add sugar in tea painter – mixes oil and colour paint you – begin your journey to school on time – 5 mins before 8 a.m. Accuracy is needed by Tailor – stitching clothes of proper fitting Chemist – Weight of various substances composing a medicine in every dosage. Averaging In scientific experiments repeated readings or measurements are taken. Then its average help us minimizing errors in measurement.

How are stands maintained How are stands maintained? The National Standard Laboratories are set up in various regions across the country for testing and certifying the weights and other measures. National Physical Laboratory (NPL – New Delhi) calibrates the measuring standards of all regional laboratories. After establishing the national standards, they are periodically checked with the world standards at the International Bureau of Weights and Measures, Paris. Thus in this way measurements made in any part of India is standardised by linking them to national and international standards.

DAY 4 TEXTUAL EXERCISE