A "mechanical wave" occurs in a physical medium because of some restoring force acting on the medium, and can be described by an amplitude, an oscillation frequency, and an amplitude.
You can easily decrease the wavelength of a mechanical wave by half by doubling the frequency ONLY if which of the following is true? Select all that apply.

a. The ratio between the restoring force and the density of the medium remain constant
b. The amplitude is doubled
c. The amplitude is reduced by 1/2
d. The same medium is used at the same temperature