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2 years ago

9

Select the correct answer. You travel in a circle, whose circumference is 8 kilometers, at an average speed of 8 kilometers/hour

. If you stop at the same point you started from, what is your average velocity? A. 0 kilometers/hour B. 2 kilometers/hour C. 4 kilometers/hour D. 8 kilometers/hour E. 16 kilometers/hour

1 answer:

BlackZzzverrR [31]2 years ago

7 0

Answer:

Since velocity is a vector quantity there is no net displacement and the average velocity is zero

(A) is correct

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7. It takes 1 second to hear the reflection of a loud noise made in front of a large barrier. If

Tpy6a [65]

Answer:

C 340 m

Explanation:

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3 years ago

Which statement correctly differentiates between transmitters and receivers?

jeka94

Answer:

Transmitters send radio waves, and receivers capture radio waves.

Explanation:

Let us look at each of the choices one by one:

(1).Transmitters have antennas, and receivers do not have antennas.

Nope. To send signals transmitters need antennas, and to receive signals the receivers need antennas as well.

(2). Transmitters send radio waves, and receivers capture radio waves.

This is true. Transmitters are for transmitting and receivers are for receiving EM signals.

(3). Transmitters have demodulators, and receivers have modulators.

No, it is the other way around. Transmitters have modulators, and receivers have demodulators.

(4). Transmitters do not have amplifiers, and receivers have amplifiers.

Nope. Both the transmitters and the receivers need amplifiers. Transmitters need them to increase the power of the broadcast, and receivers need them to amplify the signal for processing.

Therefore, only the 2nd statement "Transmitters send radio waves, and receivers capture radio waves." is correct.

7 0

3 years ago

Read 2 more answers

A 4.4-µF capacitor is initially connected to a 5.1-V battery. Once the capacitor is fully charged the battery is removed and a 2

Grace [21]

Question is incomplete. Missing part:

Find the charge on the capacitor at the following times:

1) t = 0 mu S

2) t = 1 mu S

3) t = 50 mu S

1) $22.4 \mu C$

We start by calculating the initial charge on the capacitor. For this, we can use the following relationship:

$C=\frac{Q_0}{V_0}$

where

C is the capacitance

Q0 is the initial charge stored

V0 is the initial potential difference across the capacitor

When the capacitor is connected to the battery, we have:

$C=4.4\mu F = 4.4\cdot 10^{-6}F$

$V_0 = 5.1 V$

Solving for $Q_0$ ,

$Q_0 = CV_0 = (4.4\cdot 10^{-6})(5.1)=2.24 \cdot 10^{-5} C = 22.4 \mu C$

So, when the battery is disconnected, this is the charge on the capacitor at time t = 0.

2) $20.0\mu C$

To find the charge on the capacitor at any other time t, we use the equation:

$Q(t) = Q_0 e^{-\frac{t}{RC}}$

where

$Q_0 = 22.4 \mu C$

t is the time

$R=2.0 \Omega$ is the resistance

$C=4.4\mu F$ is the capacitance

Therefore, at time $t=1 \mu s$ , we have:

$Q(t) = (22.4) e^{-\frac{1}{(2.0)(4.4)}}=20.0 \mu C$

3) $0.08 \mu C$

As before, we use again the equation:

$Q(t) = Q_0 e^{-\frac{t}{RC}}$

However, here the time to consider is

$t=50 \mu C$

Substituting into the formula,

$Q(t) = (22.4) e^{-\frac{50.0}{(2.0)(4.4)}}=0.08 \mu C$

4 0

3 years ago

Sobre un barco, que se mueve en forma rectilínea, y con velocidad constante de 30 [km/h], se mueve un perro en el mismo sentido

almond37 [142]

Answer:

El observador verá correr al perro sobre la cubierta del barco a una velocidad de 40 kilómetros por hora.

Explanation:

Para determinar la velocidad del perro con respecto al observador sentado desde la playa a través del concepto de velocidad relativa, descrito en la siguiente fórmula:

$v_{P/B} = v_{P} - v_{B}$ (1)

Donde:

$v_{P/B}$ - Velocidad del perro relativo al barco, en kilómetros por hora.

$v_{P}$ - Velocidad del perro con respecto al observador, en kilómetros por hora.

$v_{B}$ - Velocidad del barco con respecto al observador, en kilómetros por hora.

Si sabemos que $v_{B} = 30\,\frac{km}{h}$ y $v_{P/B} = 10\,\frac{km}{h}$ , entonces la velocidad del perro con respecto al observador es:

$v_{P} = v_{B} + v_{P/B}$

$v_{P} = 30\,\frac{km}{h} + 10\,\frac{km}{h}$

$v_{P} = 40\,\frac{km}{h}$

El observador verá correr al perro sobre la cubierta del barco a una velocidad de 40 kilómetros por hora.

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3 years ago

Suppose you throw a cube-shaped object and a spherical-shaped object of equal volume in the same volume of water. The ball sinks

sergeinik [125]

The objects have different densities
They objects may possess the same volume; however, due to a difference in density, they do not possess the same mass within that volume. This means that they experience a different gravitational force, which causes one to sink and the other to float.

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3 years ago