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4 years ago

12

Which statement best describes an atom? (1 point) protons and neutrons grouped in a specific pattern protons and electrons sprea

d around randomly a group of protons and neutrons that are surrounded by electrons a ball of electrons and neutrons surrounded by protons

1 answer:

sashaice [31]4 years ago

7 0

A group of protons and neutrons surrounded by electrons

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Which of the following would decrease current flow in a circuit made originally from a 6-volt battery, a loop of wire, and a swi

Oduvanchick [21]

For a given closed circuit the current voltage and resistance of circuit is related with ohm's law

$V = i*R$

here

V = voltage difference due to battery

i = current flow in the circuit

R = resistance

so from above equation

$i = \frac{V}{R}$

so in order to decrease the current in the circuit we can either increase the resistance of the circuit or decrease the voltage

Now the formula of resistance is

$R =\rho \frac{L}{A}$

here

$\rho$ = resistivity of material of resistance

$L = resistance$

A = crossectional area

a) if we use a thick wire the as per above formula of resistance the value of resistance will decrease.

And hence the current will increase in the circuit so it is not correct option

b) If 6V battery is replaced by 12 V battery then due to increase in potential difference the current in the circuit will also increase, so this is not correct answer.

c)Opening the switch will decrease the voltage from 6 V to 0 Volt

due to this decrease in potential difference the current in the circuit will also decrease. So by Opening the switch the current will be decreased in this circuit.

8 0

3 years ago

Why is thermal energy produced not generally usable to do work?

zhuklara [117]

The ability of thermal energy to dissipate too quickly and not get concentrated makes it not suitable for doing work. In addition, thermal energy comes from the rapid movement of particles in which it is directly proportional. Therefore, the faster the particle movement, more heat or thermal energy is generated.

5 0

3 years ago

Read 2 more answers

Hospital X-ray generators emit X-rays with wavelength of about 15.0 nanometers (nm), where 1nm=10−9m. What is the energy of a ph

Sergio [31]

Answer:

$E=1.32\times 10^{-17}\ J$

Explanation:

Given that,

The wavelength of x ray, $\lambda=15\ nm=15\times 10^{-9}\ m$

We need to find the energy if a photon on the x-rays. The formula for the energy of the photon is given by :

$E=\dfrac{hc}{\lambda}$

$E=\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{15\times 10^{-9}}$

$E=1.32\times 10^{-17}\ J$

So, the energy of a photon of the X-rays is $1.32\times 10^{-17}\ J$ . Hence, this is the required solution.

4 0

4 years ago

Which of these is an example of an elastic collision? A. The cue ball crashing into the eight balls on a pool table. B. Two cars

abruzzese [7]

Answer:

The cue ball crashing into the eight balls on a pool table.

Explanation:

Elastic and inelastic collisions are two types of collisions.

For elastic collision, both the momentum and the kinetic energy before and after the collision remains conserved.

Out of the given options, the option that shows an example of an elastic collision is option A " The cue ball crashing into the eight balls on a pool table." All the eight balls after crashing moves with different velocity.

7 0

3 years ago

Which of the following best describes what we mean by the universe? (A) all the galaxies in all the superclusters(B) the sum tot

EastWind [94]

Answer:

(B) the sum total of all matter and energy

Explanation:

Universe comprises of all the matter and energy that exists in space. It contains billions of stars, planets and interstellar matter that is clouds of dust and gas. There is large amount of the empty space in between.

Universe contains stars as many as grains of sand on all beaches on the Earth. These stars are grouped into galaxies. Milky Way is one of the galaxies. Galaxies can be grouped into clusters and super-clusters.

3 0

3 years ago