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
Set up a proportion
1 mile/1.6 km = 20,000miles/x
Cross Multiply
x = (20,000) * (1.6)
x = 32,000 kilometers
y=9 because you would need to subtract 3 from both sides because its a -3, adding 3 would cancel it out on one side leaving y=9. 9 is the answer:)-May
Answer:
The SI unit of pressure is Pascal .