Advertisements
Advertisements
Question
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?
Solution
The difference between the two readings is the length of the pencil.
= 12.1 cm – 2.0 cm
= 10.1 cm or 10 cm and 1 mm.
APPEARS IN
RELATED QUESTIONS
The farthest objects in our Universe discovered by modern astronomers are so distant that light emitted by them takes billions of years to reach the Earth. These objects (known as quasars) have many puzzling features, which have not yet been satisfactorily explained. What is the distance in km of a quasar from which light takes 3.0 billion years to reach us?
When the planet Jupiter is at a distance of 824.7 million kilometres from the Earth, its angular diameter is measured to be 35.72″ of arc. Calculate the diameter of Jupiter
Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):-
the number of air molecules in your classroom.
Fill in the blank.
In the ............ system, length is measured in centimetres.
Assertion (A): Distance between two celestial bodies is measured in terms of light year.
Reason (R): The distance travelled by the light in one year is one light year.
Can you find the diameter of a thin wire of length 2 m using the ruler from your instrument box?
How close was your earlier guess? Discuss.
The fencing of a square garden is 20 m in length. How long is one side of the garden?
In which SI unit, you can measure your height?
The radius of atom is of the order of 1 Å and the radius of nucleus is of the order of fermi. How many magnitudes higher is the volume of atom as compared to the volume of nucleus?