Hello, Super Mallow!

I use a slightly different set-up . . .

2) A balloon is rising vertically above a level, straight road at a constant rate of 1 ft/sec.

Just when the balloon is 65 feet about the ground,

a bicycle moving at a constant rate of 17 ft/sec passes under it.

How fast is the distance s(t) between the bicycle and the balloon increasing 3 sec later? Code:

B *
↑\
↑ \
t ↑ \
↑ \
↑ \ s(t)
P * \
| \
65 | \
| \
* → → → → *
A 17t C

The balloon is at when the cycle passes under it (at ): .

In the next seconds, the balloon rises feet to point : .

In the same seconds, the bicycle moves feet to point : .

Using Pythagorus: .

Differentiate with respect to time:

. .

And now let