Answer:
The variable manipulated or controlled by the experimenter is called the independent variable.
Example:
If the flow velocity at the bottom of a tank is measured by varying the height of water in the tank, we are measuring velocity as a function of water height.
Therefore,
water height = independent variable (controlled)
velocity = dependent variable (measured in response to water height).
Mathematically,
v = f(h)
where v = response variable (dependent)
h = controlled variable (independent).
Answer : The frequency decreases by a factor of 2.
Explanation :
Given that the wave travels at a constant speed. The speed of the wave is given as :

Where
υ is the frequency of the wave
and λ is the wavelength of the wave.
In this case, the speed is constant. So, the relation between the frequency and the wavelength is inverse.

If the wavelength increases by a factor of 2, its frequency will decrease by a factor of 2.
Hence, the correct option is (A) " The frequency decreases by a factor of 2 ".
Answer:
Explanation:
General Equation of SHM is given by


where x=position of particle
A=maximum Amplitude
angular frequency
t=time
At any time Total Energy is the sum of kinetic Energy and Elastic potential Energy i.e. 
where k=spring constant
Potential Energy is given by 
also it is given that Potential Energy(U) is equal to Kinetic Energy(K)
Total Energy
Total


at 
velocity is
According to another source this is what I got
<span>0.735 J ( Ep-potential energy, m-mass,g-gravitational acceleration = 9.81m/s², h-height; Ep = m * g * h; Ep = 0.0300 kg * 9.81 m/s² * 2.5 m )
</span>Hope it helps