Answer:

Explanation:
As we know that we board in the car of ferris wheel at the bottom position
So we will have
final height of the car at angular displacement given as


here we know that


so we have


It's very hard to see the self-portrait, so I can't identify him.
Just subsitute and easy
v=55m/s
m=100kg
KE=(0.5)(100kg)(55m/s)^2
KE=(50kg)(3025 m^2/s^2)
KE=151250 J
2nd option
By definition, the density of an object is given by:

Where,
M: mass of the object
V: volume of the object
Since the mass and volume of an object are numerical values greater than zero, then it follows that:

It is important to respect the units of each measure.
For this case we can use the grams for the mass and cubic centimeters for the volume.
Answer:
A possible value for density is given by:

Shear Stress= Force along the tangent/ Area
= 2700/π*r^2
=2700/3.14*16
=54