Answer:
The rate at which both of them are moving apart is 4.9761 ft/sec.
Step-by-step explanation:
Given:
Rate at which the woman is walking, = 3 ft/sec
Rate at which the man is walking, = 2 ft/sec
Collective rate of both, = 5 ft/sec
Woman starts walking after 5 mins so we have to consider total time traveled by man as (5+15) min = 20 min
Now,
Distance traveled by man and woman are and
ft respectively.
⇒
⇒
As we see in the diagram (attachment) that it forms a right angled triangle and we have to calculate .
Lets calculate h.
Applying Pythagoras formula.
⇒
⇒
Now differentiating the Pythagoras formula we can calculate the rate at which both of them are moving apart.
Differentiating with respect to time.
⇒
⇒
⇒ ...as
⇒ Plugging the values.
⇒ ...as
ft/sec
⇒ ft/sec
So the rate from which man and woman moving apart is 4.9761 ft/sec.
