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2 years ago

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An electric fan is set on its HIGH setting. After the Low push button is depressed, the angular speed of the fan blades decrease

s to a value of 8.00x10^2 rev/min in 1.75sec. The deceleration is 42.0 rad/s^2. Determine the initial angular speed of the blades in rev/min

1 answer:

brilliants [131]2 years ago

8 0

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.

<span>a=Δω/Δt
</span><span>a=2π*Δf/Δt
</span><span>a=2π*(f2-f1)/Δt
</span>
<span>f1=f2-a*Δt/2π
</span><span>f2=800/60 rev/sec
</span><span>a=-42 rad/sec^2
</span><span>Δt=1.75sec
</span><span>so f1=25 rev/sec
f1=1500 rev/min</span>

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La luz roja visible tiene una longitud de onda de 680 nanómetros (6,8 x 10-7 m). La velocidad de la luz es de 3.0 x108 m / s. ¿C

Lina20 [59]

Answer:

Frequency, $f=4.41\times 10^{14}\ Hz$

Explanation:

Visible red light has a wavelength of 680 nanometers (6.8 x 10⁻⁷ m). The speed of light is 3.0 x 10 ⁸ m / s. What is the frequency of visible red light?

It is given that,

Wavelength of a visible red light is, $\lambda=6.8\times 10^{-7}\ m$

Speed of light is, $c=3\times 10^8\ m/s$

We need to find the frequency of visible red light. It can be calculated using below relation.

$c=f\lambda\\\\f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{6.8\times 10^{-7}}\\\\f=4.41\times 10^{14}\ Hz$

So, the frequency of visible red light is $4.41\times 10^{14}\ Hz$ .

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2 years ago

A proton has been accelerated from rest through a potential difference of -1000 v . part a what is the proton's kinetic energy,

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We can apply the law of conservation of energy here. The total energy of the proton must remain constant, so the sum of the variation of electric potential energy and of kinetic energy of the proton must be zero:
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2 years ago

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Which of the following statements is TRUE about impulse? (Consider the Impulse-Momentum Theorem: F▲t = m ▲v )

kotykmax [81]

The statement “Impulse is a vector quantity” is true about Impulse.

Answer: Option B

<u>Explanation: </u>

The object’s action by applied force in a particular time interval, there happens changing in momentum called impulse. It is denoted by a symbol ‘J’ or ‘imp’ and expressed in a unit ‘Ns’. As impulse depends on the acted force, when a collision arises from front, behind or side, the force’s direction would be differed.

$\text {Impulse }=\text {Force } \times \text {time}=\vec{F} \Delta t$

So, from this option A is false as impulse is not a force but changing momentum. The unit is not Newton, it is Newton second (Ns). The force direction differs (impulse direction) for each cases of collision, so option D also false. Hence, option B seems to be correct. Vector quantity deals with both direction and magnitude and important in motion study.

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2 years ago

The power in an electric circuit varies inversely with the resistance. If the power is 2,200 watts when the resistance is 25 ohm

valentinak56 [21]

Answer:

The value of resistance when power is 1100 watts = $R_{2}$ = 50 ohms

Explanation:

Power $P_{1}$ = 2200 Watts

Resistance $R_{1}$ = 25 ohms

Power $P_{2}$ = 1100 Watts

Resistance $R_{2}$ = we have to calculate

Given that the power in an electric circuit varies inversely with the resistance

⇒ P ∝ $\frac{1}{R}$

⇒ $\frac{P_{2} }{P_{1} }$ = $\frac{R_{1} }{R_{2} }$

⇒ $\frac{1100}{2200}$ = $\frac{25}{R_{2} }$

⇒ $R_{2}$ = 50 ohms

This is the value of resistance when power is 1100 watts.

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