00:01
Dx upon dt equal to 1 ,250 negative 1 ,050 upon t plus 1.
00:14
It is horizontal velocity and vertical velocity is dy upon dt equal to negative 625 times t2.
00:31
T square plus 250 times t so here an aeroplane tax off at t equal to zero or flying due north it tags 24 minutes for plane to reach cruising altitude and during this time it is ground speed dx up on d t and d y up dd so here for first what is the cruising altitude of the plane so here given t equal to 24 minute so we have to convert minute to or so here we have to divide by 60 so here 24 time 1 upon 60 equal to 1 to 0 .4 are the integral of velocity is the net distance travel and we can just integrate d y upon d t since we only want to the vertical distance so here at time t equal to 0 to 0 .4 are these are the limits for integration.
02:10
Now, integral definite integral of negative 625 times t squared plus 250 time t d t from 0 to 0 .4.
02:31
So, now we have to find the anti -derivative of negative 625 times t squared plus 250 time t is negative 625 upon 3 times t cubed plus 125 times t squared from 0 to 0 .4.
03:02
So now here we have to put upper value which is 0 .4 so here t equal to 0 .4 so you put here negative 625 upon 3 time 0 .4 to the power 3 plus 125 time 0 .4 to the power 3 plus 125 time 0 .4 to the power 2 2.
03:35
Now here you can see that lower value is 0.
03:38
So here we get 0 when we put t equal to 0.
03:45
Now we simplify this and here we get approximate value 6 .67 miles.
03:56
So it is our final answer for part a.
03:59
Now we solve part b.
04:01
So here what is the ground distance covered from 10? check off until cruising altitude.
04:13
So here we know that for ground distance, distance will be horizontal.
04:19
So at t equal to 0 to t equal to 0 .4, and here we use d x upon d t.
04:35
So here definite integral of 1 ,250 negative 150 upon t plus 1 plus 1 time d t from 0 to 0 .4.
04:56
So now here we have to find 1 ,250 time 1 ,250 time, t negative 150 times natural modulus t plus 1 .4.
05:26
So now here you can see that upper value is 0 .4...