The feather's vertical position
is determined by

We take the feather's starting position to be the origin, and the downward direction to be positive. Then

so the answer is D.
You would want it to be greater than D. friction force
It needs be greater than the friction applied to it.
Kinetic energy = (1/2) (mass) (speed)²
The rock's kinetic energy is not
(1/2) (4 kg) (10 m/s)²
= (1/2) (4 kg) (100 m²/s²)
= 200 Joules .
It may be more, or it may be less. The only thing
we can be sure of is that it is not 200 Joules.
Answer:
The value is 
Explanation:
From the question we are told that
The mass of the woman is
The spring constant of the bungee cord is 
Generally the period of the oscillation (i,e time taken to complete on cycle ) is mathematically represented as

=> 
=> 