00:05
Now here we have a boat which is heading due east at a speed 33 kilometers per hour, right? relative to the water and the current is moving towards the source west at this march, right? so basically we have boat which is moving relative to the water to the east, right? and the water is itself moving source west.
00:24
So sauce west, that's going this direction, right? so this angle should be 45 degrees, right? so that is 15 kilometers per hour, right? well, this is 33 kilometers for all, right? so you also give the vector of sense actually moving the boat.
00:43
Well, that's of course the sum of these two vectors, right? so let's call this direction x, okay? and this direction y, all right? so then we can, let me call this vector, let me call it v1, okay? and this one is v2, okay? and then the actual velocity, of course, the boat is given by v equals v1 plus v2, right? now if you look at the v1, it has only x component, so it's actually 33 and 0, plus v2.
01:14
Now v2 has both components, right? so the both components actually are next here.
01:19
So i would like to put a minus sign here, minus 15 times sine times sine 45 degrees, that's square two over a very, two, right? and similarly, 15 times square root of two over two for the y component.
01:36
So, and if you do the calculation, you'll find this, of course, to be given by 33 minus 15 times, or say, divided by square root of, and that actually gives you 0 .3 .4, right? and so 22 .4, sorry, 22 .4 for the x component and the y component will be just given by minus 10 .6, right, minus 10 .6 kilometers per hour, right? so that would be the speed for you should put in this blank, right? how fast is the boom moving right to the ground? well, so how fast that's speed, right? so basically that's given by square of 20 .20 .4 squared plus 10 .6 squared, right? and if you do the calculation, that of course gives you 22 .4 squared plus 10 .6 squared.
02:35
And that actually gives you 24 .8...