Awoman 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.

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

So, the raft covered 6-2 = 4 m in 4.3 seconds

Speed = Distance / Time

Speed of the raft is 0.93 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s