Question

What distance will Sangita travel in 12 hours, if she maintains a speed of $25{\text{ m/sec}}$

Answer 1

Hint: In this question, we need to determine the total distance covered by Sangita in 12 hours if she travels at a speed of 25 meters per second. For this, we will first convert the hours to seconds and then use the relation between distance, time and speed.

Complete step-by-step answer:
First, convert all the parameters in the same units. So, here we will convert 12 hours into seconds by multiplying the absolute value by 3600. So,
$
  1hr = 3600\sec \\
  12hr = 12 \times 3600 \\
   = 43200\sec \\
 $
Now, the product of the speed and the time of the moving body results in the distance travelled by the body. Mathematically, $d = vt$ where, ‘d’ is the distance travelled by the body, ‘v’ is the speed of the body and ‘t’ is the time.
According to the question, Sangita’s speed is 25 meters per seconds, and we need to determine the distance travelled in 12 hours which is equivalent to 43200 seconds. So, substitute $v = 25{\text{ m/s}}$ and $t = 43200\sec $ in the formula $d = vt$ to determine the distance travelled by Sangita.
\[
\Rightarrow d = vt \\
   = 25 \times 43200 \\
   = 1080000{\text{ meters}} \\
 \]
Now, meters can be converted into kilometres by dividing the absolute value by 1000. So,
$\Rightarrow 1080000{\text{ meters}} = 1080km$
Hence, the distance travelled by Sangita at a speed of 25 meters per second in 12 hours is 1080 kilometres.

Note: Alternatively, we can also convert the speed from meters per second to kilometres per hour. So,
$
\Rightarrow 25{\text{ m/sec}} = \dfrac{{25}}{{1000}} \times 60 \times 60{\text{ km/hr}} \\
   = 90{\text{ km/hr}} \\
$
So, the distance travelled by Sangita is
$
\Rightarrow d = vt \\
   = 90 \times 12 \\
   = 1080km \\
 $