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4 years ago

Which of the following values of pH will change blue litmus paper red?

1 answer:

5 0

As far as I know acids turn litmus paper red and bases turn it blue. on the pH scale anything under 7 is acid and above is base so I think it is A. I am not totally sure, but that is the best answer I can give you! Good Luck! Hope this helps!!

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5. If population size temporarily exceeds the environmental _______, deaths will increase until the population size returns to p

rusak2 [61]

Answer: A. carrying capacity

A carrying capacity of the ecosystem or the environment refers to the maximum number of individuals in a population of species that an ecosystem can support in terms of available resources like food, habitat, water and other necessities. If the size of the population exceeds the environmental carrying capacity, this will result in death as all individuals will not be able to derive resources and the population size will return to previous levels.

6 0

3 years ago

In the visible spectra of stars, absorption lines of hydrogen are produced when atoms are excited from n = 2 to higher levels (t

grigory [225]

Answer:

3. relatively high temperature, about 10,000 K, so that significant numbers of electrons are excited from the ground state, n = 1, to the first excited state, n = 2, but not too many of them have been ejected completely from the atoms

Explanation:

If hydrogen absorption lines are very strong in the visible spectrum of a particular star that means the population of electron in n = 2 is very high so on being exited they absorb radiation in Balmer series and give rise to absorption spectrum. The average temperature required to excite electron in hydrogen atom from n=1 to n = 2 is 10000K .

4 0

3 years ago

A geosynchronous satellite orbits Earth at a distance of 42,250 km from the center of Earth and has a period of 1 day. What is t

yan [13]

Answer:

The centripetal acceleration of the satellite is $a=0.22\ m/s^2$ .

Explanation:

Given that,

The distance covered by a geosynchronous satellite, d = 42250 km

The time taken by the satellite to covered distance, t = 1 day = 24 hours

Since, 24 hours = 86400 seconds

Let v is the speed of the satellite. It is given by the total distance divided by total time taken such that :

$v=\dfrac{d}{t}$

$v=\dfrac{2\pi d}{t}$

$v=\dfrac{2\pi\times 42250 \times 10^3}{86400 }$

v = 3072.5 m/s

The centripetal acceleration of the satellite is given by :

$a=\dfrac{v^2}{d}$

$a=\dfrac{(3072.5)^2}{42250 \times 10^3}$

$a=0.22\ m/s^2$

So, the centripetal acceleration of the satellite is $a=0.22\ m/s^2$ . Hence, this is the required solution.

7 0

3 years ago

1. A SUV along with 5 passengers has a mass of 3500 kg. It has a driving force of 2500 N directed along west on a perfectly hori

Dovator [93]

Answer:

The net acceleration of the SUV is 0.429 meters per square second due west.

Explanation:

Statement is incomplete. Description is presented below:

<em>A SUV along with 5 passengers has a mass of 3500 kg. It has a driving force of 2500 N directed along west on a perfectly horizontal road. The surface of the road exerts a resistance force of 500 N due east. At the same time a high wind is blowing a force of 500 N due east in the opposite direction of the car's drive force. Does the car has any acceleration? If yes, then what are the magnitude and direction of the car's acceleration?</em>

According to Newton's Laws of Motion, the SUV will accelerate if and only if net acceleration is different of zero. Let suppose as positive the direction of driving force ( $F$ ), measured in newtons:

$\Sigma F = F - R -f = F_{net}$ (1)

Where:

$R$ - Resistance force, measured in newtons.

$f$ - Wind force, measured in newtons.

$F_{net}$ - SUV net force, measured in newtons.

If we know that $F = 2500\,N$ , $R = 500\,N$ and $f = 500\,N$ , then net force experimented by the SUV is:

$F_{net} = 2500\,N-500\,N-500\,N$

$F_{net} = 1500\,N$

The car has acceleration.

By definition of force for systems with constant mass, we calculate the acceleration of the vehicle below:

$a_{net} = \frac{F_{net}}{m}$ (2)

Where $m$ is the mass of the SUV, measured in kilograms.

If we know that $F_{net} = 1500\,N$ and $m = 3500\,kg$ , then the net acceleration of the car is:

$a_{net} = \frac{1500\,N}{3500\,kg}$

$a_{net} = 0.429\,\frac{m}{s^{2}}$

The net acceleration of the SUV is 0.429 meters per square second due west.

8 0

3 years ago

Morse code and string phone cup

polet [3.4K]

Answer:

Following are the responses to the given question:

Explanation:

Following are the difference in the speed and accuracy:

The biggest difference was its tone between both the cup method as well as the Morse code. One should talk using cup system and sequence system and let its covering be understood in Morse code, just a series of beeps weren’t tangible... Secondly, a method of cup involves a range string. Rukun Negara is often distributed by cable, but this is a greater range. It reaches concurrently in those other areas.

In the case of using the string method for the block, its distance and stiffness of the string are limited and the barriers are eliminated. It will certainly be convenient and clearer if one utilizes Sign language.

If two experts are acting like such a machine on both sides, their information between both the 2 persons is smoother and quicker as they will not have to wait for data from a third person which may create another pause at the time.

Morse code is faster, eventually. For some very small periods when sensitive information is not transmitted, strings or cup methods must be reserved.

8 0

3 years ago