Question

If the velocity of light is3.0×10'8metres pre second, calculated the distance travelled by light in a light year and express it in standard from

Answer 1

the given speed of the light is
$3 \times {10}^{8}$
metres per second

we already know that distance is equal to the product of the speed and the time for which the object was moving with the particular constant speed.
so
in order to find the distance travelled by the light, we need to find the time as well as the speed of the light
but
we are given with the speed.
hence,
we have to find the time.
To find the time:-
we have been given the time is equals to 1 year.
converting 1 year into hours then into minutes and then into seconds.
So,

$1year = 24hours \\ \\ 24hours = 24 \times 60minute \\ \\ 1440minute = 1440 \times 60sec \\ = 86400 \: sec$

now we have the speed of the light as well as the time in seconds.
so,
applying the formula to get the distance

$d = 3 \times {10}^{8} \times 864 \times {10}^{2} \\ \\ = 864 \times 3 \times {10}^{10} \\ \\ = 2592 \times {10}^{10} \\ \\ = 2.592 \times {10}^{13}$

when does distance covered is
2.592 * 10¹³ metre = 2.592 * 10 ^10 km

since we have to give dance in the standard unit then the correct answer will be 2.592 * 10 to the power 13 metres.

thank you!