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3 years ago

Help please

Physics

1 answer:

Anarel [89]3 years ago

4 0

Answer:

1) D, 2) D, 3) B, 4) B, 5) C

Explanation:

You are asked to select the correct answer

1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.

the correct answer is D

2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy

the correct answer is D

3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.

Correct answer B

4) speed is defined by

v = x / t

so the correct answer is B in the SI system

5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.

The correct answer is C

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2. A 1.54 kΩ resistor is connected to an AC voltage source with an rms voltage of 240 V.

svp [43]

(a) The maximum potential difference across the resistor is 339.41 V.

(b) The maximum current through the resistor is 0.23 A.

(d) The average power dissipated by the resistor is 38.4 W.

<h3>Maximum potential difference</h3>

Vrms = 0.7071V₀

where;

V₀ is peak voltage

V₀ = Vrms/0.7071

V₀ = 240/0.7071

V₀ = 339.41 V

<h3> rms current through the resistor </h3>

I(rms) = V(rms)/R

I(rms) = (240)/(1,540)

I(rms) = 0.16 A

<h3>maximum current through the resistor </h3>

I₀ = I(rms)/0.7071

I₀ = (0.16)/0.7071

I₀ = 0.23 A

<h3> Average power dissipated by the resistor</h3>

P = I(rms) x V(rms)

P = 0.16 x 240

P = 38.4 W

Learn more about maximum current here: brainly.com/question/14562756

#SPJ1

8 0

2 years ago

Are materials that dissolve in water hydrophobic or hydrophilic

stira [4]

Answer:

hydrophilic

Explanation:

hydrophobic means it hates water so a hydrophobic material would separate from the water and just sit there (an example of this is oil)

4 0

3 years ago

Read 2 more answers

I need help in this pls i really need a answer

IrinaK [193]

Answer:

In terms of distance, average speed is 20 km/h

In terms of displacement, average speed is 0 km/h.

Explanation:

Total distance:

$= (40.0 - 10.0) + (20.0 - 10.0) + (40.0 - 20.0) \\ = 30.0 + 10.0 + 20.0 \\ = 60.0 \: km$

Total time is 3.0 hours

but:

$average \: speed = \frac{total \: distance}{total \: time} \\$

In terms of distance.

substitute:

$average \: speed = \frac{60.0}{3.0} \\ \\ = 20 \: {kmh}^{ - 1}$

$displacement = ( - 30.0) + 10 .0+ 20.0 \\ = 0$

In terms of displacement:

$speed = \frac{0}{3} \\ \\ = 0 \: {kmh}^{ - 1}$

3 0

3 years ago

How is velocity different from speed?

enyata [817]

Velocity, unlike speed, includes a direction.

Velocity is a vector quantity which is defined by magnitude and direction.

Speed is a scalar quantity. It is the rate at which an object moves regardless of which direction.

5 0

3 years ago

Read 2 more answers

A 30.0-Î¼F capacitor is connected to a 49.0-Î© resistor and a generator whose rms output is 30.0 V at 60.0 Hz. (a) Find the rms

Natali5045456 [20]

Explanation:

Given that,

Capacitor = 30μC

Resistor = 49.0Ω

Voltage = 30.0 V

Frequency = 60.0 Hz

We need to calculate the impedance

Using formula of impedance

$Z=\sqrt{R^2+X_{c}^2}$ .....(I)

We need to calculate the value of $X_{c}$

Using formula of $X_{c}$

$X_{c}=\dfrac{1}{2\pi f c}$

$X_{c}=\dfrac{1}{2\times\pi\times60.0\times30\times10^{-6}}$

$X_{c}=88.42\ \Omega$

Put the value of $X_{c}$ into the formula of impedance

$Z=\sqrt{(49.0)^2+(88.42)^2}$

$Z=101.08\ \Omega$

(a). We need to calculate the rms current in the circuit

Using formula of rms current

$I_{rms}=\dfrac{V}{Z}$

$I_{rms}=\dfrac{30.0}{101.08}$

$I_{rms}=0.30\ A$

The rms current in the circuit is 0.30 A.

(b). We need to calculate the rms voltage drop across the resistor

Using formula of rms voltage

$V_{rms}=I_{rms}\times R$

Put the value into the formula

$V_{rms}=0.30\times49.0$

$V_{rms}=14.7\ V$

The rms voltage drop across the resistor is 14.7 V

(c). We need to calculate the rms voltage drop across the capacitor

Using formula of rms voltage

$V_{rms}=I_{rms}\times X_{C}$

$V_{rms}=0.30\times88.42$

$V_{rms}=26.53\ V$

The rms voltage drop across the capacitor is 26.53 V.

Hence, This is the required solution.

4 0

3 years ago