I think the correct answer would be the last option. A kind of variable that a researcher purposely changes in an investigation is the independent variable. It is the value that does not depend to any change in any variable involved. Instead, it is the one that affects the other variable called the dependent variable. The dependent variable is the variable that is being tested or studied. Also, along with these two there are variables that are held equal all through out the research. These are called the constants. These constants are factors that might affect the dependent variable that is why they are held constant to prevent more errors.
Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
Answer:
a) Fermi level = 600 electron-volts
b) 
Explanation:
Given data:
length of one-dimensional crystal = 10 um
Lattice spacing = 0.1 nm
A) Determine the Fermi level assuming one electron per atom
Total length = 10 <em>u</em>m
Interatomic separation of a = 0.1 nm
in this case the Atom has one electron therefore the number of electrons = 10^5 and the number of states Ns = gsN = 2 * 10^5 ( attached below is some part of the solution )
hence : Fermi level = 600 electron-volts
B) Determine the density of states as a function of electron energy
attached below is the detailed solution
Answer:
6 m/s
Explanation:
Given that :
mass of the block m = 200.0 g = 200 × 10⁻³ kg
the horizontal spring constant k = 4500.0 N/m
position of the block (distance x) = 4.00 cm = 0.04 m
To determine the speed the block will be traveling when it leaves the spring; we applying the work done on the spring as it is stretched (or compressed) with the kinetic energy.
i.e 





v = 6 m/s
Hence,the speed the block will be traveling when it leaves the spring is 6 m/s
Answer:
Stage 1: Infancy: Trust vs. Mistrust.
Stage 3: Preschool Years: Initiative vs. Guilt.
Stage 4: Early School Years: Industry vs. Inferiority.
Stage 6: Young Adulthood: Intimacy vs. ...
Stage 7: Middle Adulthood: Generativity vs. ...
Stage 8: Late Adulthood: Ego Integrity vs. ...
The key idea in Erikson's theory is that the individual faces a conflict at each stage, which may or may not be successfully resolved within that stage. For example, he called the first stage 'Trust vs Mistrust'. If the quality of care is good in infancy, the child learns to trust the world to meet her needs.
Explanation: