Advertisements
Advertisements
Question
Calculate the length of the arc of a circle of radius 31.0 cm which subtends an angle of `pi/6` at the centre.
Solution
Plane Angle α = `"Arc length"/"Radius" = s/r`
According to the problem, θ = `pi/6 = s/31` cm
Hence, length of arc = s = `31 xx pi/6` cm`
= `(31 xx 3.14)/6` cm
= 16.22 cm
Rounding off to three significant figures it would be 16.2 cm.
APPEARS IN
RELATED QUESTIONS
What do you mean by significant figures?
How many significant figures should be present in the answer of the following calculation:-
`(0.02856 xx 298.15 xx 0.112)/0.5785`
How many significant figures should be present in the answer of the following calculation?
5 × 5.364
A LASER is a source of very intense, monochromatic, and unidirectional beam of light. These properties of a laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. A laser light beamed at the Moon takes 2.56 s to return after reflection at the Moon’s surface. How much is the radius of the lunar orbit around the Earth?
It is a well known fact that during a total solar eclipse the disk of the moon almost completely covers the disk of the Sun. From this fact and from the information you can gather from examples 2.3 and 2.4, determine the approximate diameter of the moon.
State the number of significant figures in the following:
6.032 N m–2
State the number of significant figures in the following:
0.0006032 m2
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 wind speed during a storm
The number of significant figures in 0.06900 is ______.
The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give ______.
