00:01
Okay, so this problem has several parts.
00:02
The first part just wants to know the vector components of the velocity imparted on a ship by its engine.
00:10
So we know that the direction is going to, well, let's do the magnitude.
00:15
So the engine is 22 miles per hour.
00:21
20 miles per hour.
00:26
So that's our magnitude of our vector.
00:28
And the direction of our vector is 35 degrees east of south.
00:32
So if we draw a quick diagram, 35 degrees east of south means that this angle is 35 degrees.
00:41
So if we add that to 270, we'll have that our angle that the ship is putting onto us, i guess, is 305 degrees.
00:54
So to calculate the components, we do u is equal to our magnitude times the cosine of our angle given and 20 times the sign of our angle given.
01:17
Okay, so we just have to put those in our calculator.
01:19
So 20 times cosine of 305 is 11 .47 miles per hour in the eastern direction.
01:37
And then for the sign, 16 .38 in the southern direction.
01:53
Okay, so there's part a.
01:57
Part b says if the wind is blowing from north to south at 12 miles per hour, so the wind, let's call it w, our vector for the, that will be none east to west and north to south means it's going to be negative 12 and then it says find the magnitude and direction of the net velocity of the ship so we have to add that to our u vector which we just got so our u vector was 11 .47 and negative 12 and negative 16 is negative 28 our decimal will stay the same at 0 .38 okay so the sum of our wind and engine w plus u is going to be 11 .47 i guess i already added the so it'll be negative 28 .38.
03:13
So that's the wind plus the engine so this part just needs to stay 16.
03:18
That was just me rewriting it's got ahead of myself so the engine would give us negative 16.
03:24
Okay so wind plus engine that's our vector components of that so we need to know the magnitude and direction of the net velocity so magnitude i would would be the sum of the squares.
03:39
And then take the square root.
03:53
And that's just calculator works.
03:55
And we go plug those in.
04:11
So the magnitude is going to be 30 .61 miles per hour.
04:24
And then our direction, we can just do tan inverse...