Question

mh grade 9 bridge course scien... course: mh grade 9 bridge... > unit 15 unit test sound unit test hey, lets keep the momentum! on to week 2 of your streak! 1 week streak level 2 0 / 2 skills part 1: move arms up and down once every second. part 2: move arms up and down twice every second. move arms the same vertical distance as in part 1. compare the periodic waves she makes in each part of the workout. from part 1 to part 2 of the workout, the frequency, the wavelength, and the amplitude. the energy transferred down the rope every second. 3 of 10 skip check

Explanation:

Step1: Define frequency

Frequency is the number of wave - cycles per second. In part 1, arms move up and down once per second (frequency $f_1 = 1\ Hz$), in part 2, arms move up and down twice per second ($f_2=2\ Hz$). So the frequency increases.

Step2: Recall wave - speed formula

The wave - speed formula is $v = f\lambda$, where $v$ is the wave speed (constant in this case as the medium is the same). Since $v$ is constant and $f$ increases, from $\lambda=\frac{v}{f}$, the wavelength $\lambda$ decreases.

Step3: Define amplitude

Amplitude is the maximum displacement from the equilibrium position. It is stated that the vertical distance of arm - movement is the same in both parts, so the amplitude remains the same.

Step4: Recall energy formula

The energy transferred per second in a wave is proportional to $f^2A^2$. Since $A$ is constant and $f$ increases, the energy transferred down the rope every second increases.

Answer:

Increases, Decreases, Stays the same, Increases