Advertisements
Advertisements
Question
How many stamps can be placed along its length?
Advertisements
Solution
Measure the length of the stamp already placed on it with the help of a ruler.
Length of stamp = 2 cm.
Thus, we can place 7 stamps along the length of the rectangle.
APPEARS IN
RELATED QUESTIONS
The principle of ‘parallax’ in section 2.3.1 is used in the determination of distances of very distant stars. The baseline AB is the line joining the Earth’s two locations six months apart in its orbit around the Sun. That is, the baseline is about the diameter of the Earth’s orbit ≈ 3 × 1011m. However, even the nearest stars are so distant that with such a long baseline, they show parallax only of the order of 1” (second) of arc or so. A parsec is a convenient unit of length on the astronomical scale. It is the distance of an object that will show a parallax of 1” (second) of arc from opposite ends of a baseline equal to the distance from the Earth to the Sun. How much is a parsec in terms of meters?
What are the S.I. units of
- mass
- length
- time and
- temperature.
Write their names and symbols.
Answer the following question.
Star A is farther than star B. Which star will have a large parallax angle?
Length of one’s chest can be measured using metre scale.
A hand span is a reliable measure of length.
Metre is the unit of ______.
Guess the lengths to draw these things. Ask your friend to draw the same. After you make the drawing use a scale to measure the length. Whose drawing showed a better guess?
| Guess its length and draw |
Measure of your drawing |
Measure of your friend’s drawing |
| An ant of length less than 1 cm |
||
| Pencil of length about 7 cm |
||
| A glass 11 cm high with water up to 5 cm |
||
| A bangle of perimeter 20 cm |
||
| A curly hair of length 16 cm |
What is the length of a 100 rupee note? Guess. Now measure it using a scale.

Measure the yellow rectangle. It is ________ cm long.
How wide is the rectangle? ________ cm
How close was your earlier guess? Discuss.
Arbaz plans to tile his kitchen floor with green square tiles. Each side of the tile is 10 cm. His kitchen is 220 cm in length and 180 cm wide. How many tiles will he need?

You can play this game on the ground. Make two squares of one square meter each. Divide your class into two teams. Ready to play!
- Which team could make more children sit in their square? How many?
In which SI unit, you can measure your height?
What is the unit of measurements of very small lengths?
What is the unit of length?
To measure the distance of a planet from the earth, ______ method is used.
- 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.
What is an Astronomical Unit (AU)?
