Answer:
0.93 m/s
Explanation:
t = Time taken
u = Initial velocity = 0
v = Final velocity
s = Displacement = 90 m
a = Acceleration = 9.81 m/s²
[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow 90=0\times t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{90\times 2}{9.81}}\\\Rightarrow t=4.3\ s[/tex]
So, the raft covered 6-2 = 4 m in 4.3 seconds
Speed = Distance / Time
[tex]\text{Speed}=\frac{4}{4.3}=0.93\ m/s[/tex]
Speed of the raft is 0.93 m/s