15 ellen is at a hydroplane boat show. starting from 1.0 miles away, the boat drives towards her and then passes her. the boat passes at a constant rate of 70 miles per hour. ellen is given by d=l1.0-70tl. at what time is the boat 0.15 miles from ellen? calculate your answer in seconds.

D = d + Vt,
d = 1.0 miles,
V = -70 miles per hour,(- because its coming towards you)
And about D
Imagine you're standing at the centre of the street. a car is coming towards you. You can easily see that car will be X miles away from you two times. When Driving towards you And When Driving away from you. So
we have two D. + 0.15 miles and -0.15 miles.
0.15= 1 - 70t
-0.15=1-70t
From here
t equals
either
0.85/70 hours which is 0.85/70*3600 second about 43.7 sec.
or
1.15/70 hours or 1.15*3600/70 about 59 sec.

It would take her 20 minutes.

Answer: b 2 = 1.

step-by-step explanation: given equation a = h(b 1+b 2)

also we are given values of a, h and b 1 as :

a = 16, h = 4, and b 1 = 3.

in order to solve it for b 2, we need to plug the given values of   a, h and b 1 .

therefore, plugging values of   a, h and b 1   in given equation, we get

16 = 4( 3 + b 2)

first dividing both sides by 4, we get

4 = 3 + b 2

subtracting 3 from both sides, we get

4 -3 = 3 -3 + b 2

1 = b 2.

therefore, b 2= 1.