00:02
The ball started with initial speed 0 and falling with acceleration g.
00:09
So acceleration a will be equals to dv by dt.
00:13
So from here we will get v with time equals to gt.
00:18
And also the displacement s is 0 at the top of building and it is increasing as the ball falls.
00:24
So we can write that v equals to ds by dt.
00:28
So from here we get s with respect to time is g3.
00:33
Square by 2 okay so from here time t comes out to be 2 s by g under root okay and t with respect to n which comes out to be 2 multiplied by 10 multiplied by n by 32 .174 okay 10 is the height of each story building and n is the number of buildings okay so this is the time it takes to ball and it takes the ball to get from the top of nth floor to pass it.
01:09
Okay? so from here we can write that t n equals to t n minus t n minus 1.
01:19
This is the time required to pass from nath floor to n minus 1th floor.
01:24
Okay.
01:25
So for the first condition in which we have to determine the time taken to pass from the first story.
01:33
So we can write that t1 will be equals to t1 minus t0.
01:40
Okay, one will be this that is n equals to 1...