All categories

4 years ago

Kepler’s 1st Law states that ________________________.

2 answers:

8 0

Kepler's 1st Law states that planets move in elliptical path. The correct option among all the options given in the question is option "B".Kepler was the person that set out to determine the path of planets with the sun at the center. By the method of trial and error, he discovered the fact that the sun lied at the focus and the planets revolved around it in a elliptical path. This discovery changed the way people thought about the movement of planets and sun. <span> </span>

Dima020 [189]4 years ago

8 0

Kepler's 1st law of planetary motion says that planets move in
orbits that are ellipses, with the sun at one focus of the ellipse.

(Choice D. is the idea behind Kepler's 3rd law.
Choices A. and C. have no basis in fact at all.)

You might be interested in

The older, geocentric model of the solar system placed the__________ at the center. Today's heliocentric model places the_______

DedPeter [7]

the answer is earth for the first one and sun for the second one

3 0

3 years ago

Read 2 more answers

Need help now due in 5 minutes

rjkz [21]

Answer:

I'm positive it's the last one

Explanation:

6 0

4 years ago

What affect would using a 12V car battery have on the operation of your circuit? (Do not try this.) What would happen to the cur

k0ka [10]

Answer:

Incomplete question

This is the completed question

If the resistor in the circuit had a larger resistance then the current would be then have to be proportionally smaller. Because the batteries each give off 1.5 volts then the current would have to be the variable that would change. What affect would using a 12V car battery have on the operation of your circuit? (Do not try this.) What would happen to the current? What would happen to the resistor?

Explanation:

Using ohms law as our basis

Ohms law state that, the voltage in an ohmic conductor is directly proportional to the current

V∝I

Resistance is the constant of proportionality

Then

V=iR

Since we want a relationship between current and resistance.

then, I=V/R

So, current is inversely proportional to Resistance

as the current increase the resistance reduce and as the current reduces the resistance increases.

a. So, increasing the voltage from 1.5V to 12V increases the current In the circuit because voltage Is directly proportional to I.

From ohms law

V=iR

When v =1.5V

I=1.5/R

When V increase to 12V

I=12/R

I.e, it increases by a factor of 8. Eight times it's initial value

b. Now, the resistance in the circuit is the constant of proportionality and it doesn't change in a given circuit expect when using a variable resistoa r like rheostat.

6 0

3 years ago

A fire truck emits an 880Hz siren. As the truck approaches an observer on the sidewalk, he perceives the pitch to be 950Hz. Appr

Ludmilka [50]

Answer:

The pitch that he hears after the truck passes and is moving away is 819.6 Hz.

Explanation:

The pitch that he hears after the truck passes and is moving away can be calculated using the following equation:

$f = f_{0}*\frac{v_{s} \pm v_{o}}{v_{s} \pm v_{f}}$

Where:

$f$ : is the perceived frequency

$f_{0}$ : is the emitted frequency

$v_{s}$ : is the speed of sound = 340 m/s

$v_{o}$ : is the speed of the observer = 0 (he is not moving)

$v_{f}$ : is the speed of the fire truck

First, we need to find the speed of the fire truck. When it approaches the observer we have:

$f = f_{0}*\frac{v_{s} + v_{o}}{v_{s} - v_{f}}$

$950 Hz = 880 Hz*\frac{340 m/s}{340 m/s - v_{f}}$

$v_{f} = 340 m/s - \frac{880 Hz*340 m/s}{950 Hz}$

$v_{f} = 25.05 m/s$

Hence, the speed of the fire truck is 25.05 m/s.

Now, we can calculate the pitch that the observer hears after the truck passes:

$f = f_{0}*\frac{v_{s} - v_{o}}{v_{s} + v_{f}}$

$f = 880 Hz*\frac{340 m/s}{340 m/s + 25.05 m/s}$

$f = 819.6 Hz$

Therefore, the pitch that he hears after the truck passes and is moving away is 819.6 Hz.

I hope it helps you!

7 0

3 years ago

Electromagnetic waves are used extensively in modern technology. Many devices are built to emit and/or receive EM waves at a ver

il63 [147K]

Answer: Option D and E

Explanation: Across the electromagnet spectrum, the frequency increases but the wavelength reduces.

This implies that radio waves have the longest wavelength but the smallest frequency, while gamma rays have the shortest wavelength but the highest frequency.

This implies that there is an inverse relationship between wavelength and frequency.

Of all the technologies listed above, wireless internet has the highest frequency hence making it have the shortest wavelength.

Also by comparing values from the data given to us above, it is possible for some wireless internet device to operate within the same frequency range of the microwave.

3 0

3 years ago