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3 years ago

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A speeder is pulling directly away and increasing his distance from a police car that is moving at 24 m/s with respect to the gr

ound. The radar gun in the police car emits an electromagnetic wave with a frequency of6.7 × 10 9 Hz. The wave reflects from the speeder’s car and returns to the police car, where its frequency is measured to be 370 Hz less than the emitted frequency. Find the speeder’s speed with respect to the ground.

1 answer:

iogann1982 [59]3 years ago

8 0

2,062,305 2,062,305 <span>2,062,305</span>

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Which two of the following reduce the background noise in magneto- medicine?

horrorfan [7]

Answer:

The answer is b.) and d.)

Explanation:

The options to reduce the background noise in magneto-medicine are given as follows:

a.) Orienting the heart parallel to the Earth's field

- This will have no significant effect on the measurements.

b.) Taking the difference of two nearby sensor measurements (gradiometer).

-This answer is TRUE.

c.) Placing the heart in a perpendicular fashion to the Earth's magnetic field.

_ This answer also will not have any significant effect on measurements.

d.) Using physical means to shield environmental fields.

- This answer is TRUE.

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3 years ago

In recent years, astronomers have found planets orbiting nearby stars that are quite different from planets in our solar system.

BartSMP [9]

Answer:

The value of g in Kepler-12b is $3.85 m/s^{2}$

Explanation:

To determine the value of g at Kepler-12b it is necessary to combine the equation of the weight and the equation for the Universal law of gravity:

$W = m.g$ (1)

Where m is the mass and g is the value of the gravity

$F = G \frac{M.m}{R^{2}}$ (2)

Equation (1) and equation (2) will be equal, since the weight is a force acting on the object as a consequence of gravity:

$m.g = G \frac{M.m}{R^{2}}$ (3)

Then g will be isolated from equation 3:

$g = G \frac{M.m}{m.R^{2}}$

$g = \frac{G.M}{R^{2}}$ (4)

The radius of Jupiter has a value of 69911000 meters, so its diameter can be determined by:

$d = 2R$ (5)

Where d and R are the diameter and radius of Jupiter

$d_{jupiter} = 2(69911000 m)$

$d_{jupiter} = 139822000 m$

Procedure for finding the radius of Kepler-12b:

For the case of Kepler-12b it has a diameter that is 1.7 times that of Jupiter

$d_{Kepler-12b} = 1.7(d_{jupiter})$

$d_{Kepler-12b} = 1.7(139822000 m)$

$d_{Kepler-12b} = 237697400 m$

By means of equation 5 the radius of Kepler-12b can be known:

$R_{Kepler-12b} = \frac{d}{2}$

$R_{Kepler-12b} = \frac{237697400 m}{2}$

$R_{Kepler-12b} = 118848700 m$

Procedure for finding the mass of Kepler-12b:

The mass of Jupiter has a value of $1.898x10^{27}$ kilograms

For the case of Kepler-12b it has a mass that is 0.43 times that of jupiter

$m_{Kepler-12b} = 0.43(m_{jupiter})$

$m_{Kepler-12b} = 0.43(1.898x10^{27} Kg)$

$m_{Kepler-12b} = 8.161x10^{26} Kg$

The value of g in Kepler-12b can be found by replacing its radius and mass in equation 4:

$g = \frac{(6.67x10^{-11} N.m^{2}/Kg^{2})(8.161x10^{26} Kg)}{(118848700 m)^{2}}$

$g = 3.85 m/s^{2}$

Hence, in Kepler-12b the gravity has a value of $3.85 m/s^{2}$

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3 years ago

Which statement is accurate about how the aurora borealis is formed?

g100num [7]

Answer:

When the electrons jump to a higher energy state, they release energy as electromagnetic radiation, light.

Explanation:

When the solar wind gets past the magnetic field and travels towards the Earth, it runs into the atmosphere. As the protons and electrons from the solar wind hit the particles in the Earth's atmosphere, they release energy – and this is what causes the northern lights.

7 0

3 years ago

Why are identical bulbs arranged in a series circuit with a battery less bright than those arranged in a parallel circuit with t

tatuchka [14]

Explanation:

Resistors connected in series obey the following equation:

$R_{\rm eq} = R_1 + R_2 + R_3 + ...$

Resistors connected in parallel obey the following equation:

$\frac{1}{R_{\rm eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + ...$

The total current of the circuit will obey the Ohm's Law: V = IR. And the current will be divided across the resistors (bulbs) depending on their resistances. So, if a bulb has a higher resistance, then its current will be lesser, and it will be less bright. If a bulb has a lower resistance, then its current will be higher, and it will be brighter.

According to the above resistances connected in series and parallel, clearly, the resistances (bulbs) connected in series will have more resistance in total, and therefore less current will flow across them, and they will be less bright.

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3 years ago

Compared to the size and density of Earth, the Moon has a A. smaller diameter and lower density B. smaller diameter and higher d

MrRa [10]

Answer:

(a) Moon has smaller diameter and lower density than earth

Explanation:

Moon has smaller diameter than earth earth has a diameter of 12742 km whereas moon has a diameter of 3474.21 km

So for density density is given by $density=\frac{mass}{volume}$

From the relation we can see that density is dependent on mass and volume directly proportional to mass and inversely proportional to diameter

But in case of earth and moon mass is more dominating than volume so density is less for moon than earth

6 0

3 years ago