Answer:
b) 6.03 seconds
c) 43.164 m/s
Explanation:
t = Time taken
u = Initial velocity = 16 m/s
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²
[tex]v=u+at\\\Rightarrow 0=16-9.81\times t\\\Rightarrow \frac{-16}{-9.81}=t\\\Rightarrow t=1.63 \s[/tex]
[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow s=16\times 1.63+\frac{1}{2}\times -9.81\times 1.63^2\\\Rightarrow s=13.05\ m[/tex]
So, the stone would travel 13.05 m up
So, total height of the stone would fall is 13.05+80 = 93.05 m
[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow 93.05=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{93.05\times 2}{9.81}}\\\Rightarrow t=4.4\ s[/tex]
b) The stone will land 1.63+4.4 = 6.03 seconds later
[tex]v=u+at\\\Rightarrow v=0+9.81\times 4.4\\\Rightarrow v=43.164\ m/s[/tex]
c) The stone's velocity when it lands is 43.164 m/s
