Which of the following is a TRUE statement about the differences between electromagnetic and mechanical waves?

The specific heat of substance A is greater than that of substance B. Both A and B are at the same initial temperature when equa

Sonja [21]

Answer:

$m_A c_{pA} (T_{fA} -T) = m_B c_{pB} (T_{fB}- T)$

For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:

d) More information is needed

(The relation between the masses is not given)

Explanation:

For this case we know the following info:

$c_{pA} > c_{pB}$

Where c means specific heat for the substance A and B.

We also know that the initial temperatures for both sustances are equal:

$T_{iA}= T_{iB}$

We assume that we don't have melting or vaporization in the 2 substances. So we just have presence of sensible heat given by this formula:

$Q = m c_p \Delta T$

And for this case we know that Both A and B are at the same initial temperature when equal amounts of energy are added to them, so then we have this:

$Q_A = Q_B$

And if we replace the formula for sensible heat we got:

$m_A c_{pA} \Delta T_A = m_B c_{pB} \Delta T_B$

And if we replace for the change of the temperature we got:

$m_A c_{pA} (T_{fA} -T_{iA}) = m_B c_{pB} (T_{fB}- T_{iB})$

And since $T_{iA}= T_{iB}= T$ we have this:

$m_A c_{pA} (T_{fA} -T) = m_B c_{pB} (T_{fB}- T)$

For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:

d) More information is needed

(The relation between the masses is not given)

4 0

3 years ago

Is a dog chasing its tail acceleration

AfilCa [17]

Answer:

if he is chasing his tail faster with each circle, then that would be acceleration, If not then no

7 0

2 years ago

Read 2 more answers

A temperature of 20°c is equivalent to approximately

Yanka [14]

C would be your answer

8 0

3 years ago

Read 2 more answers

1) Si un mango cae a una velocidad de 75m/s y tarda 26 seg. en caer. ¿ Cuál habrá sido la velocidad con qué el mango llegó al su

Lyrx [107]

Answer:

El mango llega al suelo a una velocidad de 329.982 metros por segundo.

Explanation:

El mango experimenta un movimiento de caída libre, es decir, un movimiento uniformemente acelerado debido a la gravedad terrestre, despreciando los efectos de la viscosidad del aire y la rotación planetaria. Entonces, la velocidad final del mango, es decir, la velocidad con la que llega al suelo, se puede determinar mediante la siguiente fórmula cinemática:

$v = v_{o}+g\cdot t$ (1)

Donde:

$v_{o}$ - Velocidad inicial, en metros por segundo.

$v$ - Velocidad final, en metros por segundo.

$g$ - Aceleración gravitacional, en metros por segundo al cuadrado.

$t$ - Tiempo, en segundos.

Si sabemos que $v_{o} = -75\,\frac{m}{s}$ , $g = -9.807\,\frac{m}{s^{2}}$ y $t = 26\,s$ , entonces la velocidad final del mango es:

$v = v_{o}+g\cdot t$

$v = -75\,\frac{m}{s}+\left(-9.807\,\frac{m}{s} \right)\cdot (26\,s)$

$v = -329.982\,\frac{m}{s}$

El mango llega al suelo a una velocidad de 329.982 metros por segundo.

8 0

2 years ago

What heat transfer occurs when warm air rises

Leni [432]

Convection. When a fluid such as air or water touches a hot object, it can heat up and then move in bulk as a fluid, thereby carrying the heat quickly to new locations. Hot air rising is a common example of heat convection.

3 0

2 years ago