Advertisements
Advertisements
Question
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.
- Find the area of lake B on the drawing in square cm. What is its actual area in square km?
Advertisements
Solution
Lake B has 15 fully filled squares and 11 half-filled or more than half-filled squares.
- Area of 15 fully filled squares
= 15 × 15
= 225 square cm
We consider the area of every single half-filled or more than half-filled square as 1-centimetre square.
- Thus, the area of 11 such squares
= 11 × 11
= 121 square cm - So, the total area of lake B
= 225 + 121
= 346 square cm
We are given 1 cm on drawing = 1 km on the ground
Therefore, 346 square cm on drawing = 346 km
APPEARS IN
RELATED QUESTIONS
What are the S.I. units of
- mass
- length
- time and
- temperature.
Write their names and symbols.
While measuring the length of a sharpened pencil, the reading of the scale at one end is 2.0 cm and at the other end is 12.1 cm. What is the length of the pencil?
Find the answer for the following questions within the grid.
- 10-3 is one ______
- SI Unit of time is ______
- Cross view of reading a measurement leads to ______
- ______ is the one what a clock reads.
- ______ is the amount of substance present in an object.
- ______ can be taken to get the final reading of the recordings of different students for a single measurement.
- ______ is a fundamental quantity.
- ______ shows the distance covered by an automobile
- A tailor uses ______ to take measurements to stitch the cloth.
- Liquids are measured with this physical quantity.
Can you find the diameter of a thin wire of length 2 m using the ruler from your instrument box?
Numerical Problem.
Inian and Ezhilan argue about the light year. Inian tells that it is 9.46 × 1015 m and Ezhilan argues that it is 9.46 × 10 12 km. Who is right? Justify your answer.
Have you seen frogs? Where? How many different types of frogs have you seen? Are all the frogs of the same length? Here are two interesting examples.
Guess whose tail is the longest. Now measure the tails. How good is your guess?
What is the length of a 100 rupee note? Guess. Now measure it using a scale.
How many stamps can be placed along its length?
Can you think of how to cut a postcard so that you can pass through it?
Chumki, Jhumri, and Imran need wire to make a fence.
- How much wire in all will the three need?
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 B?
Length is a fundamental quantity.
What are the materials needed to find the length of a banana?
What is the unit of measurements of very small lengths?
The distance between one end and the other end is called ______.
Length is ______.
Larger unit for measuring time is ______.
- The earth-moon distance is about 60 earth radius. What will be the diameter of the earth (approximately in degrees) as seen from the moon?
- Moon is seen to be of (½)°diameter from the earth. What must be the relative size compared to the earth?
- From parallax measurement, the sun is found to be at a distance of about 400 times the earth-moon distance. Estimate the ratio of sun-earth diameters.
Consider a sunlike star at a distance of 2 parsecs. When it is seen through a telescope with 100 magnification, what should be the angular size of the star? Sun appears to be (1/2)° from the earth. Due to atmospheric fluctuations, eye can’t resolve objects smaller than 1 arc minute.
