Advertisements
Advertisements
प्रश्न
There are two beautiful lakes near a village. People come for boating and picnics in both the lakes. The village Panchayat is worried that with the noise of the boats the birds will stop coming. The Panchayat wants motorboats in only one lake. The other lake will be saved for the birds to make their nests.
- How many kilometers long is the actual boundary of lake A?
Advertisements
उत्तर
Here, the scale is 1 cm = 1 km
So, the length of the actual boundary of lake A = 30 km
APPEARS IN
संबंधित प्रश्न
What are the S.I. units of
- mass
- length
- time and
- temperature.
Write their names and symbols.
Fill in the blank.
In the ............ system, length is measured in centimetres.
Solve the numerical example.
When the planet Jupiter is at a distance of 824.7 million kilometers from the Earth, its angular diameter is measured to be 35.72'' of arc. Calculate the diameter of Jupiter.
500 gm = ______ kilogram.
Complete the analogy.
Height of a person: cm :: Length of your sharpened pencil lead:______?
Fill in the following chart.
| Property | Definition | Basic Unit | Instrument used for measuring |
| Length | |||
| Mass | |||
| Volume | |||
| Time |
Can you find the diameter of a thin wire of length 2 m using the ruler from your instrument box?
Which line is longer? C or D? Measure each line. How good is your guess?
Now guess the length and width of many other things. Measure and find the difference between your measure and your guess.
| Size of | Your guess in cm | Your measure in cm | ||
| Length | Width | Length | Width | |
| 100 Rupee note | ||||
| 10 Rupee note | ||||
| 20 Rupee note | ||||
| 5 Rupee note | ||||
| Post card | ||||
| Math-Magic book | ||||
How many stamps are needed to cover the rectangle?
How close was your earlier guess? Discuss.
Match the following:
| Prefix | Symbol | ||
| a. | Centi | i. | k |
| b. | Nano | ii. | c |
| c. | Mili | iii. | n |
| d. | Kilo | iv. | m |
Give some examples of larger length measures.
What is the unit of length?
Length is ______.
The Unit used to measure length ______.
SI unit of electric current is ______.
The SI unit of mass is kg.
In an experiment to estimate the size of a molecule of oleic acid 1 mL of oleic acid is dissolved in 19 mL of alcohol. Then 1 mL of this solution is diluted to 20 mL by adding alcohol. Now 1 drop of this diluted solution is placed on water in a shallow trough. The solution spreads over the surface of water forming one molecule thick layer. Now, lycopodium powder is sprinkled evenly over the film and its diameter is measured. Knowing the volume of the drop and area of the film we can calculate the thickness of the film which will give us the size of oleic acid molecule.
Read the passage carefully and answer the following questions:
- Why do we dissolve oleic acid in alcohol?
- What is the role of lycopodium powder?
- What would be the volume of oleic acid in each mL of solution prepared?
- How will you calculate the volume of n drops of this solution of oleic acid?
- What will be the volume of oleic acid in one drop of this solution?
What is an Astronomical Unit (AU)?
