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4 years ago

A pulley system operates with 40% efficiency. if the work put in is 200 joules, how much useful work is produced?

2 answers:

8 0

<span>1. </span><span>Efficiency is the measure of how efficient a process is. It is used to assess the ability of a process in avoiding waste energy, materials, money and time in doing a desirable output. It is calculated as;

Efficiency = useful energy ouput / total energy input</span>

<span>.40 = useful work / 200</span>

<span>useful work = 80 joules</span>

FinnZ [79.3K]4 years ago

5 0

Answer:

The useful work produced by a pulley system is 80 Joules.

Explanation:

Efficiency is a measure of how much work is preserved in a process. The formula for efficiency is the energy output, divided by the energy input, expressed as a percentage. A perfect process would have an efficiency of 100%.

η = efficiency (Greek letter "eta")

Wo = the work or energy produced by a process. Units are Joules (J).

Wi = the work or energy put in to a process. Units are Joules (J).

$n = \frac{Wo}{Wi}$

$0.4 = \frac{Wo}{200J}$

Wo = 0.4*200J

Wo = 80 J

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3 years ago

When power and current are known use R = P/I^2 to calculate the resistance.

inna [77]

<h2> $\bf{ \underline{Given:- }}$ </h2>

$\sf• \: Power \:( P) = 300 \: watts$

$\sf• \: Current \: (I) = 30 \: amps$

$\\$

<h2> $\bf{ \underline{To \: Find:- }}$ </h2>

$\sf• \: The \: Resistance$

$\\$

$\huge\bf{ \underline{Solution :-:- }}$

$\bf \red {\bigstar{ Formula \: of \: Power \: (P) = \frac{ {I}^{2} }{R}}}$

$\sf \rightarrow 300= \frac{ {30}^{2} }{ R}$

$\sf \rightarrow 300 = \frac{900}{ R}$

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$\bf \purple{Hence, \: the \: resistance \: is \: 0.33 \: Ω \: . }$

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Tension refers to the pulling force in a string which acts in an opposite direction to the force pulling on it.

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Assume the angle the ropes make with the vertical are both θ.

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Therefore, the tension, T, in each rope is T = mg/2Sinθ

Learn more about tension at: brainly.com/question/14336853

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