Answer:
a) 7.848 m/s
b) 3.156 m
Explanation:
t = Time taken
u = Initial velocity = 1.75 m/s
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²
[tex]v=u+at\\\Rightarrow 0=1.75-9.81\times t\\\Rightarrow \frac{-1.75}{-9.81}=t\\\Rightarrow t=0.18\ s[/tex]
[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow s=1.75\times 0.18+\frac{1}{2}\times -9.81\times 0.18^2\\\Rightarrow s=0.156\ m[/tex]
His highest height above the board is 0.156 m
b) Total height he would fall is 3+0.156 = 3.156 m
[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow 3.156=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{3.156\times 2}{9.81}}\\\Rightarrow t=0.8\ s[/tex]
He is in the air for 0.8+0.18 = 0.98 seconds
[tex]v=u+at\\\Rightarrow v=0+9.81\times 0.8\\\Rightarrow v=7.848\ m/s[/tex]
a) His velocity when he hits the water is 7.848 m/s
