Question

the speed of sound waves through two different media, steel and air, was recorded.
according to the graph, sound waves travel

• through steel, but not through air.
• faster through steel than through air.
• faster through air than through steel.
• through steel and air at similar speeds.

pregunta 5
1 puntos
how is it possible for gamma waves to travel at the same speed as microwaves even though gamma waves have a much larger frequency?

• the wavelength of microwaves are much smaller than gamma waves.
• the wavelength of microwaves are much larger than gamma waves.
• they only travel at the same speed in air.
• the frequency of radio waves is compensated by its smaller wavelength.

Explanation:

First Question (Bar Graph on Sound Speed)

Step1: Analizar la gráfica de barras

La gráfica muestra la velocidad del sonido en acero (Steel) y en aire (Air). La barra para acero es más alta que la para aire.

Step2: Evaluar las opciones

• "through steel, but not through air": La barra de aire no es cero, así que el sonido sí viaja por aire. Incorrecto.
• "faster through steel than through air": La barra de acero es más alta, lo que significa mayor velocidad. Correcto.
• "faster through air than through steel": Contradice la gráfica. Incorrecto.
• "through steel and air at similar speeds": Las barras tienen alturas muy diferentes. Incorrecto.

La relación entre velocidad ($v$), frecuencia ($f$) y longitud de onda ($\lambda$) es $v = f \times \lambda$. Si dos ondas electromagnéticas (como gamma y microondas) tienen la misma velocidad (en el vacío o en un medio), y la frecuencia de gamma ($f_{\gamma}$) es mayor que la de microondas ($f_{\text{micro}}$), entonces la longitud de onda de microondas ($\lambda_{\text{micro}}$) debe ser mayor que la de gamma ($\lambda_{\gamma}$) para mantener $v$ constante ($f_{\gamma}\lambda_{\gamma}=f_{\text{micro}}\lambda_{\text{micro}}$).

• Opción 1: "The wavelength of microwaves are much smaller than gamma waves": Incorrecto, debería ser mayor.
• Opción 2: "The wavelength of microwaves are much larger than gamma waves": Correcto, cumple con $v = f\lambda$.
• Opción 3: "They only travel at the same speed in air": Las ondas electromagnéticas viajan a la misma velocidad en el vacío (y en medios transparentes, no solo en aire). Incorrecto.
• Opción 4: "The frequency of radio waves is compensated by its smaller wavelength": Habla de ondas de radio, no de microondas y gamma. Incorrecto.

Answer:

B. faster through steel than through air.

Second Question (Gamma and Microwaves)