I):final velocity=initial velocity+acceleration due to gravity*time of travel
Therefore,
v=0+9.8*3.1
=30.38 m/s
If by floor you meant water bed then i think there isn't enough info in the question.
When she reaches the top, she has more potential energy than she had at the bottom.
Potential energy = (mass) x (gravity) x (height)
= (40 kg) x (9.8 m/s²) x (5 m)
= 1,960 more joules .
Power = (energy) / (time)
= (1,960 joules) / (7 seconds)
= 280 watts
(about 0.375 horsepower)
The answer is constant acceleration.
Energy can be one answer! There are many, but energy is a main one.