Help with Question

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Matt2007

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I am unsure if I worked the question out correctly and would be really grateful if someone could check it or prompt me with a hint so I could solve it right.

question 1.jpganswer 1.jpg
I set the function equal to 5 because it was the minimum height required for the ship to enter however I am unsure if that was the thing I was supposed to do
calc 1.jpg
From my working I graphed this which is, sin (x) , and , y = 1/3, and I assume that the time in which the ship can pass is between those 2 intersections as they are also above the y = 1/3 line.

Any help I would be really thankful for :)
 
Matt2007 said:
I am unsure if I worked the question out correctly and would be really grateful if someone could check it or prompt me with a hint so I could solve it right.

View attachment 28730View attachment 28731
I set the function equal to 5 because it was the minimum height required for the ship to enter however I am unsure if that was the thing I was supposed to do
View attachment 28732
From my working I graphed this which is, sin (x) , and , y = 1/3, and I assume that the time in which the ship can pass is between those 2 intersections as they are also above the y = 1/3 line.

Any help I would be really thankful for :)
Click to expand...
Did you find all safe windows between 0 and 12h?
 
Matt2007 said:
I am unsure if I worked the question out correctly and would be really grateful if someone could check it or prompt me with a hint so I could solve it right.

View attachment 28730View attachment 28731
I set the function equal to 5 because it was the minimum height required for the ship to enter however I am unsure if that was the thing I was supposed to do
View attachment 28732
From my working I graphed this which is, sin (x) , and , y = 1/3, and I assume that the time in which the ship can pass is between those 2 intersections as they are also above the y = 1/3 line.

Any help I would be really thankful for :)
Click to expand...
It is correct - except:

sin-1(1/3) = 0.33984 or 5.943345 (in radians)

30*t = 0.33984 or 2.8018 or 6.6230 or 9.08494 or 12.90621...........

t = 0.01133 or 0.093392 or 0.22077 or 0.3028 ...... and continue

This creates a very narrow window of operation of the ship. So I suspect the examiner had intended (mistakenly) that Sin-1(x) will be calculated in degrees - like you did.

It is an an excellent idea is to include the graphical solution. I would include a vertical line at t = 12.
 
Subhotosh Khan said:
Everything is correct - except:

sin-1(1/3) = 0.33984 or 5.943345 (in radians)

30*t = 0.33984 or 5.943345

t = 0.01133 or 0.19811 ...... and continue

It is an an excellent idea is to include the graphical solution. I would include a vertical line at t = 12
Click to expand...
I will do thank you!
 
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