Answer:
a) Vf = 13.87[m/s]
b) t = 1 [s]
Explanation:
a)
To solve this problem we can use kinematics equations:
[tex]v_{f}^{2}= v_{i}^{2}+(2*g*h)[/tex]
where:
Vf = final velocity [m/s]
Vi = initial velocity = 4 [m/s]
h = elevation = 9 [m]
g = gravity acceleration = 9.81 [m/s^2]
[tex]v_{f}=\sqrt{(4)^{2} +(2*9.81*9)}\\v_{f}=13.87[m/s][/tex]
b)
Now using the next equation we can find the time
[tex]v_{f}=v_{i} +(g*t) \\t = (13.87-4)/9.81\\t=1[s][/tex]