1 and 4 are tire.
2 and 3 are not.
Answer:
422.36 N
Explanation:
given,
time of rotation = 4.30 s
T = 4.30 s
Assuming the diameter of the ring equal to 16 m
radius, R = 8 m


v = 11.69 m/s
now, Force does the ring push on her at the top





N = 422.36 N
The force exerted by the ring to push her is equal to 422.36 N.
Let
be the height of the building and thus the initial height of the ball. The ball's altitude at time
is given by

where
is the acceleration due to gravity.
The ball reaches the ground when
after
. Solve for
:


so the building is about 16 m tall (keeping track of significant digits).
The magnetic particles are mixed with other substances to make it flexible.