Answer:
D. The period would decrease by sqrt (2)
Explanation:
The period of a mass-spring system is given by:

where
m is the mass
k is the spring constant of the spring
If the spring constant is doubled,
k' = 2k
So the new period will be

So the correct answer is
D. The period would decrease by sqrt (2)
All of the following would be questions that could be scientifically investigated except A.
That is an opinion and cannot become a fact.
Answer: has wavelengths that are longer than visible light
Explanation: Electromagnetic spectra comprises of different electromagnetic waves which are arranged in order of increasing wavelengths or decreasing energies.
In order from highest to lowest energy, the waves are arranged as: gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.

E= energy
h= planck's constant
c= velocity of light
= wavelength
As wavelength and energy are inversely related, the wave having higher wavelengths will be lowest in energy. Thus as infrared radiation have lower energy as compared to visible radiation. Thus infrared radiation have higher wavelength as compared to visible radiation.
Answer:
no you would not hear an echo if you shouted in your bedroom
Explanation:
Echo is a sound produced when the original sound is reflected by walls of a given room. ... So for the case of a bedroom, no echo is produced because there are stuff and the furniture block the sound from reaching the wall hence no bouncing back of sound.
so sorry if i'm wrong :)