Question

Wind is blowing west to east along two parallel tracks two trains moving with same speed in opposite direction have the steam track of one double that of other, the speed of each train is:

Answer 1

Hint: In this question, we will use the relation between speed, distance and time. Further, by substituting the given values in the question and solving the equation will give us the required result. Also, we will discuss the basics of speed and velocity.
Formula used:
$d = \left( {v \pm w} \right)t$

Complete answer:
Let us assume, v be the velocity of the train, w be the velocity of the wind.
Now, according to the question:
$x = \left( {v - w} \right)t............(1)$
$2x = \left( {v + w} \right)t.............(2)$
Now, by taking ratio of the equation (2): (1), we get:
$\dfrac{{2x}}{x} = \dfrac{{\left( {v + w} \right)t}}{{(v - w)t}}$
Further solving the above equation we get:
$2v - 2w = v + 2$
$\therefore v = 3w$
Therefore, we get the required answer, which tells that the speed of each train is three times the wind.

Additional information:
We already know the basic difference of speed and velocity i.e., speed is the measure of how fast an object can travel, whereas velocity tells us the direction of this speed. Speed is a scalar quantity that means it has only magnitude, whereas velocity is a vector quantity that means it has both magnitude and direction. The S.I unit of velocity is meter per second (m/sec).
A speedometer also called a speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. It is mostly mounted on bikes, cars, scooters. We also know that the speedometer used to measure the speed of a vehicle and the entire vehicle indicate speed in km/h.
It is also important to know that these speedometers are now universally fitted to motor vehicles; they started to be available as options in the early 20th century, and were available and used as standard equipment from about 1910 onwards. Many modern speedometers are electronic.

Note:
Here, it is important to remember most speedometers have a maximum limit up to 140-160 mph. We know that the S.I unit of speed is m/sec but the speedometer shows the value in km/h. Therefore, the question can be directly solved by having an idea of the unit of speed.