Question

4. Express the number appearing in the following statements in standard form.
(a) The distance between Earth and Moon is 384,000,000 m.
(b) Speed of light in vacuum is 300,000,000 m/s.
(c) Diameter of the Earth is 1,27,56,000 m.
(d) Diameter of the Sun is 1,400,000,000 m.
(e) In a galaxy there are on an average 100,000,000,000 stars.
(f) The universe is estimated to be about 12,000,000,000 years old.
(g) The distance of the Sun from the centre of the Milky Way Galaxy is estimated to
be 300,000,000,000,000,000,000 m.
(h) 60,230,000,000,000,000,000,000 molecules are contained in a drop of water
weighing 1.8 gm.
() The earth has 1,353,000,000 cubic km of sea water.
() The population of India was about 1,027,000,000 in March, 2001.​

Answer 1

Answer:

Given :-

Distance covered by the satellite = 450 km

Velocity of the satellite = 120 m/s

To Find :-

Time taken by the satellite.

Analysis :-

Here we are given with the distance and the speed of the satellite.

In order to find the time taken substitute the given values in the question accordingly such that time is equal to distance covered divided by the time taken.

Solution :-

We know that,

d = Distance

s = Speed

t = Time

Using the formula,

\underline{\boxed{\sf Time \ taken=\dfrac{Distance \ covered}{Time \ taken}}}

Time taken=

Time taken

Distance covered

Given that,

Distance (d) = 450 km = 450000

Speed (s) = 120 m/s

Substituting their values,

⇒ t = s/t

⇒ t = 450000/120

⇒ t = 45000/12

⇒ t = 3750 sec

Therefore, the time taken by the satellite is 3750 sec.