Answer
The answer is below.
Work Step by Step
a) We know that the frequency is directly related to the value of omega, and we know that the value of omega is directly related to the square root of k. Thus, if the frequency is doubled, the spring constant is four times as great. The spring constant is directly related to the energy, so if the spring constant of the first system is four times as great, its energy is four times as great as well.
b) We know that acceleration is directly related to the square of omega. Thus, if omega is doubled for the first system, the first system's acceleration will be four times as great.
