Respuesta :
During the final second of its fall, it falls a distance of 38m.
Its average speed during that final second was 38 m/s.
But we know that it gained 9.8 m/s of speed during that second.
Its speed at the end of that second must have been (38+4.9) = 42.9 m/s ,
and at the beginning of that second must have been (38-4.9) = 33.1 m/s .
Since its speed at the beginning of the final second was 33.1 m/s,
that final second began at (33.1/9.8) = 3.378 seconds after the drop.
All together, when the final second is added onto that, the object
fell for a total of 4.378 seconds.
Distance of fall from rest = (1/2) (g) (t)²
= (4.9 m/s²) (4.378 s)²
= (4.9 m/s²) (19.163 s²)
= 93.9 meters .
Its average speed during that final second was 38 m/s.
But we know that it gained 9.8 m/s of speed during that second.
Its speed at the end of that second must have been (38+4.9) = 42.9 m/s ,
and at the beginning of that second must have been (38-4.9) = 33.1 m/s .
Since its speed at the beginning of the final second was 33.1 m/s,
that final second began at (33.1/9.8) = 3.378 seconds after the drop.
All together, when the final second is added onto that, the object
fell for a total of 4.378 seconds.
Distance of fall from rest = (1/2) (g) (t)²
= (4.9 m/s²) (4.378 s)²
= (4.9 m/s²) (19.163 s²)
= 93.9 meters .
The height [tex]h[/tex] from which the object was released from is 93.9m.
Since object is released from rest
Initial velocity; [tex]u = 0m/s[/tex]
First, we find the velocity [tex]v[/tex] of the object at the beginning of the last second.
During the final second of its fall, it traverses a distance of 38m
Distance travelled [tex]h_1 = 38m[/tex] ( final second; time [tex]t = 1s[/tex] )
Using the second equation of motion:
[tex]s = ut + \frac{1}{2}at^2[/tex]
We substitute in our values
[tex]38m = (v * 1s) + ( \frac{1}{2} * 9.8m/s^2 * (1s)^2 )\\\\38m = (v * 1s) + 4.9m\\\\(v * 1s) = 38m - 4.9 m\\\\(v * 1s) = 33.1m\\\\v = 33.1m/s[/tex]
Now Lets find the height [tex]h[/tex] as the object transverse, final velocity [tex]v = 33.1m/s[/tex], initial velocity [tex]u = 0m/s[/tex] and acceleration due to gravity; [tex]a = 9.8m/s^2[/tex]
From the Third Equation of Motion:
[tex]v^2 = u^2 + 2ah[/tex]
We substitute in our values
[tex](33.1m/s)^2 = 0m/s + (2 * 9.8m/s^2 * h )\\\\1095.61m^2/s^2 = 19.6m/s^2 * h \\\\h = \frac{1095.61m^2/s^2}{19.6m/s^2}\\\\h = 55.9m[/tex]
So [tex]h_2 = 55.9m[/tex]
To get the height from which the ball was released:
Height = [tex]h_1 + h_2[/tex]
Height = [tex]38m + 55.9m[/tex]
Height = [tex]93.9m[/tex]
Therefore, the height [tex]h[/tex] from which the object was released from is 93.9m.
Learn more; https://brainly.com/question/14232141