We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
122
3
avatar+220 

In the harbor a ferry boat is being pulled from one side to the other with a heavy cable. If another boat has to pass, the captain of the ferry lets the cable drop to the bottom of the canal. The cable hangs in the form of a parabola. The formula h = 0,02d^2 - 0,6d + 1 applies to one of the three situations above. In this formula d is the horizontal distance in metres from the left side of the quay h is the height in metres of the cable from the waterline. 

 

a. Explain to which situation the formula h = 0,02d^2 - 0,6d + 1 applies.

b. Answer the same question for the formula h = 1/225 a^2 and - 30/225 a + 1 .

 Feb 28, 2019

Best Answer 

 #1
avatar+18449 
+3

In the first scenario, h will be a positive number

in the second drawing h = 0

in the third scenario h will be some negative number

 

.02 d^2 - 0.6 d +1     will have a nadir (a low point) at  -b/2a   =  -  -0.6/(2*.02) = 15 m = d

 

SUstitute this value in for d    .02(15^2) - 0.6(15) + 1 = h  = = -3.5    so this applies to the third picture.

 

 

 

DO the same thing for this equation   a (low point) = - b/ 2a = 15  (again)

    now substitute this value into the equation and find   h   to see what scenario this second equation fits....... you can do it!   cheeky

 Feb 28, 2019
 #1
avatar+18449 
+3
Best Answer

In the first scenario, h will be a positive number

in the second drawing h = 0

in the third scenario h will be some negative number

 

.02 d^2 - 0.6 d +1     will have a nadir (a low point) at  -b/2a   =  -  -0.6/(2*.02) = 15 m = d

 

SUstitute this value in for d    .02(15^2) - 0.6(15) + 1 = h  = = -3.5    so this applies to the third picture.

 

 

 

DO the same thing for this equation   a (low point) = - b/ 2a = 15  (again)

    now substitute this value into the equation and find   h   to see what scenario this second equation fits....... you can do it!   cheeky

ElectricPavlov Feb 28, 2019
 #3
avatar+220 
0

I do kinda get what you're doing, just not how you get the low point. I'm not the greatest at math :/ Thanks for the answer! So:

h = 1/225 a^2

h = 1/225 * 15^2

1/225 * 15^2 = 1/225 * 225 = 1

h = 1

 

and

 

- 30/225 * a + 1

- 30/225 * 15 + 1

- 2 + 1 = -1

h = -1

HeyxJacq  Mar 1, 2019
 #2
avatar+101856 
+1

Nice, EP  !!!

 

 

cool cool cool

 Feb 28, 2019

4 Online Users

avatar
avatar