Answer:
   k = 6,547 N / m
Explanation:
This laboratory experiment is a simple harmonic motion experiment, where the angular velocity of the oscillation is
          w = √ (k / m)
angular velocity and rel period are  related
          w = 2π / T
substitution
          T = 2π √(m / K)
in Experimental measurements give us the following data
   m (g)     A (cm)    t (s)   T (s)
   100        6.5         7.8    0.78
   150        5.5          9.8   0.98
    200      6.0        10.9    1.09
    250       3.5        12.4    1.24
we look for the period that is the time it takes to give a series of oscillations, the results are in the last column
         T = t / 10
To find the spring constant we linearize the equation
         T² = (4π²/K)    m
therefore we see that if we make a graph of T² against the mass, we obtain a line, whose slope is
          m ’= 4π² / k
where m’ is the slope
            k = 4π² / m'
the equation of the line of the attached graph is
        T² = 0.00603 m + 0.0183
therefore the slope
        m ’= 0.00603  s²/g
     we calculate
          k = 4 π² / 0.00603
           k = 6547 g / s²
we reduce the mass to the SI system
          k = 6547 g / s² (1kg / 1000 g)
          k = 6,547 kg / s² =
          k = 6,547 N / m
let's reduce the uniqueness
          [N / m] = [(kg m / s²) m] = [kg / s²]
 
        
             
        
        
        
Not sure what the given options are, but the answer is the horizontal component. This is given by Force x cos(angle), or Fcos(θ), where θ is the angle. In this case that would be 20cos(30) = 17.32N
        
             
        
        
        
A heat pump that uses work to move heat
        
             
        
        
        
Answer:
You can say that they "change" in speed or "slow" in speed.
Note wavelength where y is the wavelength and N the index of refraction:
N1 y1 = N2 y2
If N1 is air (N1 = 1) and N2 = 1.33 then 
y1 = 1.33 y2
Since y2 is less the speed will be smaller