Respuesta :

Answer:

Below

Explanation:

To find the height of a ball thrown upwards we can use this formula :

     vf^2 = vi^2 + 2ad

     0^2 = 22^2 + 2(-9.8)d

     484 = 19.6d

     24.69 = d

     25 m = d

To find the time of the phone dropped we can use this formula :

     t = √2d/g

     t = √2(15) / 9.8

     t = √30/9.8

     t =√3.142857

     t = 1.749

    t = 1.7 seconds

For a) since this object is free falling we know that it will accelerate towards earth at a rate of 9.8 m/s^2. The slope of a velocity time graph gives us the acceleration of the object. So in this case the slope would be 9.8 m.s^2

Hope this helps!