Worksheet: Measurement

Transcription

1 Worksheet: Measurement 1. Humans have the need to measure and quantify everything such as weight, height, speed, temperature, etc. And one of the most important parts of measurement is a unit. Let us spend some time understanding the history behind units. Did you know that in old Briton the length of the king s foot was use as a standard of measurement? This unit later was refined and given the definition by which we use it today. Standard units like the foot are fundamental units from which we can derive other units. For instance, from foot written as ft we derive ft/second, ft 2, etc. Try and find out brief histories of the following standard units. Name of unit Brief history Foot Celsius Kilogram Second 2. Accurate and precise are words that we use very often. With the help of a dictionary and the Web try and understand both these words and write their meaning below with a few examples. Precise Accurate

2 3. Using the span of your hand as a standard measuring unit of length, find out the lengths of the following objects. Object Length in hand span (hs) Book Table Your room A pen A geometry box An A4 size paper 4. While measuring the lengths of the objects in the above exercise what were the difficulties that you faced? Write in the space provided below When using the span of our hands as measuring unit for length, we find it difficult to measure lengths that are less than one hand span. In order to take care of this any measuring instrument is divided into many sub units. Observe the following measuring instruments and write down the total number of divisions between any two consecutive units. For example, for an inch tape the total number of divisions is 1 cm or 1 inch. Inch tape Scale Spring balance Speedo metre Watch Wall clock Thermometer 6. Least count: Least count of any measuring instrument is the smallest quantity the instrument can measure with utmost precision For example, in most scales there are 10 divisions between any two centimeters i.e., 10 divisions =1 centimeter 1division = 1/10 centimeter = 0.1 centimeter

3 The scale can measure 0.1 centimeter with utmost precision, hence the least count of the scale is 0.1 cm. Find out the least count of the following measuring instruments that we use every day. Measuring instrument Watch Clock Thermometer Speedometer of scooter/car Least count 7. Noise pollution: Carry out a research on noise pollution using books and internet sources and answer the following questions. i. What is the measuring unit of noise pollution? ii. Up to which degree is noise pollution acceptable? iii. Mahatma Gandhi said, We must become the change we want to see. Reflect and write below the steps you will take to reduce noise pollution.

4 8. Observe your home and write the type of angles present in your home along with their estimated measurements. Type of angle Estimated measurement 9. My body measures There are many quantitative measurements related to a healthy body like blood pressure, heart beat, hemoglobin count, etc. With the help of your parents/doctor/friends complete the following table and write a reflective note after comparing standard measures and measurements of your body. Sl. No. Measuring Parameters 1 Blood Pressure 2 Hemoglobin count 3 Weight 4 Height 5 My Body Mass Index Standard Measures Male Female Measure related to my body Reflective Note

5 10. We measure things for consumption, experiment and other purposes. In the table given below research and write down all the measuring units used to measure area, volume, mass, weight and length. Area Volume Mass Weight Length 11. Take your electricity bill and telephone bill and discuss with your parents to answer the following questions. i. In what unit is the electricity supplied to your home measured? ii. Write a brief about the above unit after discussion & web research. iii. What are the basics on which telephone bills are generated? 12. We use the unit of degree to measure angles i.e., 90 o, 60 o, 70 o, etc., and also to measure temperature, i.e., 76 0 C, 28 o C, etc. Write briefly the similarities and differences in their usage. Degree for measuring angles Degree for measuring temperature Similarities Differences