The ducks speed is 10m per second
Answer:
The period of the system of ladder and woman, T = 2.5 seconds
Explanation:
Mass of the ladder, 
Mass of the artiste, 
Length of the ladder, L = 42.0 kg
The total moment of inertia can be calculated using the equation:

D = L/2 = 3/2
D = 1.5 m
The frequency of the system of ladder and woman follows that of a physical pendulum which can be given by the equation:

The period of the system of ladder and woman is given by:
T = 1/f
T = 1/0.4
T = 2.5 seconds
A single prolonged blast emitted by a boat using an efficient sound producing devices indicates that the boat is leaving the dock. It may also be used to indicate that the boat is moving and for alarming other vessels, but in this case, one prolonged blast is followed by two short blasts, in two minutes of time.
"Free fall" is the motion of an object when gravity is the ONLY force
acting on it.
In true 'free fall' the speed of an object increases at a constant rate
for the total duration of the fall. The rate of increase, on or near the
Earth's surface, is 9.8 meters per second for each second of fall.
True free fall is almost impossible to observe in everyday life, because
whenever we see anything falling, it's almost always falling through air,
so gravity is NOT the only force acting on it. The friction due to the
motion through air works against the gravitational force. In many cases,
the result is that the object's speed eventually stops increasing and
becomes constant, at a speed often described with the faux technical,
high-fallutin' sounding phrase "terminal velocity". It must be understood
that 'terminal velocity' is NOT a property of gravity or of free fall, but is
only a result of falling through some surrounding stuff that interferes with
the process of true 'free fall'.