Answer:
a) Â y = yâ‚€ - 4.9, v = -9.8 m / s, b) Â y =yâ‚€ - 19.6, Â v = - 19 m / s
c) Â y =yâ‚€ - 44.1, v = - 29.4 m / s
Explanation:
To solve this exercise let us use the kinematic relations
     y =y₀ + v₀ t - ½ g t²
     v = v₀ - g t
They indicate that the body is released therefore the initial velocity is zero vâ‚€ = 0
     y = y₀ - ½ g t²
     v = - gt
a) the position and velocity for t = 1s
     y = y₀ - ½ 9.8 12
     y = y₀ - 4.9
     v = - 9.8 1
     v = -9.8 m / s
the negative sign indicates that the velocity is directed downwards
b) t = 2 s
     y =y₀ - ½ 9.8 2 2
     y =y₀ - 19.6
     v = - 9.8 2
     v = - 19 m / s
c) t = 3 s
    y = y₀ - ½ 9.8 3 2
    y =y₀ - 44.1
    v = - 9.8 3
    v = - 29.4 m / s