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3 years ago

Which statement describes the atomic number?

1 answer:

6 0

Answer:The term atomic number, conventionally denoted by the symbol Z, indicates number of protons present in the nucleus of an atom, which is also equal to the number of electrons in an uncharged atom. The number of neutrons is represented by the neutron number (N)

Explanation:

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Please answer quick for brainlist ; )

balandron [24]

Answer:

The diagram assigned B

explanation:

Check the direction of the two vectors, their resultant must be in the same direction.

7 0

3 years ago

An alternator provides 20 A of peak current at 100 V peak AC to a resistive electric heater. How much heating power is delivered

Liono4ka [1.6K]

-- The resistance of the heater is (volts/current) = 5 ohms

-- The heating (RMS) value of a sinusoidal AC is V(peak)/√2 . For this particular alternator, V(peak)=100V, so the heating (RMS) equivalent is 70.71 V.

-- The heating power delivered to the electric heater is (E²/R).

Power = (100/√2)² / 5

Power = 5,000 / 5

Power = 1,000 watts

6 0

3 years ago

If we decrease the distance an object moves we will (2 points)

Fantom [35]

Decrease the amount of force applied

8 0

3 years ago

Read 2 more answers

A car initially traveling at 17.1 mph comes to rest in 9.7s what was its acceleration in this time?

ra1l [238]

Answer:

$a=-.78m/s^2$

Explanation:

Δ $v=at$

Δ $v$ is the difference in velocity before and after a given time.
$a$ is the acceleration of the object during this time.
$t$ is time

$(v_f-v_i)=at$ is another way to write this equation.

The Δ symbol represents "the difference between the initial and final values of a magnitude or vector", so Δ $v=(v_f-v_i)$

$v_f-v_i=at\\\frac{at}{t}=\frac{v_f-v_i}{t}\\a=\frac{v_f-v_i}{t}$

I rearranged this equation to solve for $a$ , but this is a step that you don't need to take, it's just good to get in the habit of doing this.
Plug in the given values. Note that our final velocity is $0$ , because the car travels until at rest.

$a=\frac{v_f-v_i}{t}\\a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}$

Our initial velocity is in mph, something not in standard units, so if not changed, you will get an incorrect answer. What you need to do is cancel out the units your prior value had using division and multiplication, and at the same time multiply and divide the correct numbers and units into your equation. Or look up a converter.

$a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}\\a=\frac{0m/s-7.6m/s}{9.7s} \\a=\frac{-7.6m/s}{9.7s}$

if you converted correctly, your answer for $v_f$ will be ≅ $7.6m/s$ .
Now divide. Notice that the units for acceleration are $m/s^2$ or meters per second, per second.

$a=\frac{-7.6m/s}{9.7s}\\a=-.78m/s^2$

Our final answer is negative because the car is slowing down. Do not square this answer as the square symbol only applies to the units, not the magnitude.

4 0

3 years ago

Read 2 more answers

Theo made a list of the properties of electromagnetic waves. Identify the mistake in the list. Electromagnetic Wave Properties 1

lapo4ka [179]

Answer:

Line 3 has a mistake.

Explanation:

Electromagnetic waves consist of oscillations of electric and magnetic fields that oscillate perpendicular to the each other. Therefore, Line 1 is correct.

Also, the fields in an electromagnetic waves oscillate perpendicular to the direction of propagation of the wave: therefore, they are transverse waves. So Line 2 is also correct.

Electromagnetic waves, contrary to mechanical waves, do not need a medium to propagate: so, they can also travel through a vacuum. Therefore, Line 3 is wrong.

Finally, all electromagnetic waves travel through a vacuum at the same speed, called speed of light:

$c=3\cdot 10^8 m/s$

So, Line 4 is also correct.

3 0

3 years ago

Read 2 more answers

Which statement describes the atomic number?​

Which statement describes the atomic number?