You have to take note of the individual directions of the plane. Since one is heading east, and the other is heading west, the planes are heading at opposite directions. So, it means that their distance between each other would be equal to 1,200 miles which accounts for the sum of their individual distances. The equation is as follows:
Total Distance = Distance of slower plane + Distance of faster plane
1,200 miles = st + (30+s)(t)
where
s is the speed of the slower plane and t is the time. Since both are not given, the final answer would just be in terms of s.
1,200 = t(s + 30 + s)
t = 1200/(30+2s)
t = 600/(15+s)
Answer:
Diana's speed relative to ground is <u>16 km/h</u> in the direction of motion of train.
Explanation:
Given:
Velocity of train in forward direction is,
Here,
Velocity of Diana relative to train in the backward direction is,
Negative sign implies backward motion or motion opposite to the direction of train's motion. Here, Diana is walking from front of train to back. So, Diana is moving in the opposite direction.
Now, we know that, for two bodies 'A' and 'B', velocity of 'A' relative to ground is given as:
Therefore, velocity of Diana relative to ground is given as:
So, Diana's speed relative to ground is 16 km/h in the direction of motion of train.
Answer: B
Explanation: If she is interested in it then yes