contestada

A woman on a bridge 90.0 m high sees a raft floating at
aconstant speed on the river below. She drops a stone fromrest in
an attempt to hit the raft. The stone is releasedwehn the raft has
6.00 m more to travel before passing under thebridge. The stone
hits the water 2.00 m in front of theraft. Find the speed of the
raft.

Respuesta :

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