Many things can affect a material's resistance, The type of material, how the material is being held (If its laying flat, being pulled, etc). What the material is used for, and how much material there is. Hope this helps!
Answer:

Explanation:
Given
-- initial velocity
--- height
Required
Determine the time to hit the ground
This will be solved using the following motion equation.

Where

So, we have:


Subtract 30.2 from both sides





Solve using quadratic formula:

Where




Split the expression
or 
or 
Time can't be negative; So, we have:


Hence, the time to hit the ground is 1.82 seconds
Most marine bioluminescence is blue-green, which is easier to see in the deep ocean
Explanation:
As per science, Emission and production of light by a living organism is defined as Bioluminescence. Bioluminescence occurs widely in marine animals whereas it is triggered by a physical disturbance is seen by humans, such as a moving boat hull or waves.
Throughout the water column bioluminescent organisms live and bioluminescence is extremely common in deep sea which shows that visible spectrum is more limited to marine animals than humans.
Answer: I = 111.69 pA
Explanation: The hall effect is all about the fact that when a semiconductor is placed perpendicularly to a magnetic field, a voltage is generated which could be measured at right angle to the current path. This voltage is known as the hall voltage.
The hall voltage of a semiconductor sensor is given below as
V = I×B/qnd
Where V = hall voltage = 1.5mV =1.5/1000=0.0015V
I = current =?,
n= concentration of charge (electron density) = 5.8×10^20cm^-3 = 5.8×10^20/(100)³ = 5.8×10^14 m^-3
q = magnitude of an electronic charge=1.609×10^-19c
B = strength of magnetic field = 5T
d = thickness of sensor = 0.8mm = 0.0008m
By slotting in the parameters, we have that
0.0015 = I × 5/5.8×10^14 × 1.609×10^-19×0.0008
0.0015 = I×5/7.446×10^-8
I = (0.0015 × 7.446×10^-8)/5
I = 111.69*10^(-12)
I = 111.69 pA
This is easily explained saying that the frictional force between the books and the paper isn't big enough to produce a displacement in the books. The displacement in the books doesn't happen because the frictional force between the books and the surface they are standing on is bigger than the paper's one.