Electroreception is limited to aquatic environments because on here is the resistivity of the medium is low enough for electric currents to be generated as the result of electric fields of biological origin. In air, the resistivity of the environment is so high that electric fields from biological sources do not generate a significant electric current. Electroreceptor are found in a number of species of fish, and in at least one species of mammal, the Duck-Billed platypus.
Answer:
B. 1700 Hz, 5100 Hz
Explanation:
Parameters given:
Length of ear canal = 5.2cm = 0.052 m
Speed of sound in warm air = 350 m/s
The ear canal is analogous to a tube that has one open end and one closed end. The frequency of standing wave modes in such a tube is given as:
f(m) = m * (v/4L)
Where m is an odd integer;
v = velocity
L = length of the tube
Hence, the two lowest frequencies at which a dog will have increased sensitivity are f(1) and f(3).
f(1) = 1 * [350/(4*0.052)]
f(1) = 1682.69 Hz
Approximately, f(1) = 1700 Hz
f(3) = 3 * [350/(4*0.052)]
f(3) = 5048 Hz
Approximately, f(3) = 5100 Hz
Answer:
The answer is gravitational force
Explanation:
According to the information given, the Heisenberg uncertainty principle would be given by the relationship
Here,
h = Planck's constant
= Uncertainty in velocity of object
= Uncertainty in position of object
m = Mass of object
Rearranging to find the position
Replacing with our values we have,
Therefore the uncertainty in position of electron is 
Answer:
Explanation:
For this problem we must use Newton's second law where force is gravitational attraction
F = m a
Since movement is circular, acceleration is centripetal.
a = v2 / r
Let's replace
G m M / r² = m v² / r
G M r = v²
The distance r is from the center of the planet
r = R + h
v = √ GM / (R + h)
If the friction force is not negligible
F - fr = m a
Where the friction force must have some functional relationship, for example
Fr = b v + c v² +…
Suppose we are high enough for the linear term to derive the force of friction
G m M / r - (m b v + m c v2) = m v2
G M / r - b v = v²
We see that the solution of the problem gives lower speeds and that change over time.
To compensate for this friction force, the motors should be intermittently suspended to recover speed.
