Introduction
Length is a fundamental physical quantity that helps us determine how long or short an object is. Measurement of length is crucial in everyday life, engineering, architecture, and science.
Units of Length
1. Non-Standard Units
- Handspan: Distance from the thumb to the little finger.
- Cubit: Length from the elbow to the middle finger.
- Footstep: Length of a step taken by a person.
2. Standard Units
- Millimeter (mm)
- Centimeter (cm)
- Meter (m)
- Kilometer (km)
Conversion of Units
Understanding conversions between units is essential:
- 1 km = 1000 m
- 1 m = 100 cm
- 1 cm = 10 mm
Example: Convert 5 km to meters:
5 km = 5 × 1000 = 5000 meters.
Measuring Instruments
- Ruler
- Measuring Tape
- Meter Rod
- Odometer
- Vernier Caliper
Methods of Measuring Length
1. Direct Measurement
Using rulers, measuring tapes, etc.
2. Indirect Measurement
Used for large distances like roads or rivers.
Word Problems
Problem: A rope is 6 meters long. If it is cut into 3 equal parts, what is the length of each part?
Solution: 6 m ÷ 3 = 2 m each.
Summary
Length measurement is an essential concept that involves units, conversions, and different tools for accuracy.