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Ksenya-84 [330]
3 years ago
8

A department store expects to have 225 customers and 20 employees at peak times in summer. Determine the contribution of people

to the total cooling load of the store. The average rate of heat generation from people doing light work is 115 W, and 70% of it is in sensible form.
Physics
1 answer:
stiks02 [169]3 years ago
3 0

Answer:

<em>The  contribution of people to the cooling load of the store is 19722.5 W</em>

Explanation:

Total amount of customers = 225

Total amount of employees = 20

Total amount of people in the store at that instant n = 245 people

Average rate of heat generation Q = 115 W

percentage of these heat generated that is sensible heat = 70%

Sensible heat raises the surrounding temperature. Latent heat only causes a change of state.

The total heat generated by all the people in the store = n x Q

==> 245 x 115 = 28175 W

but only 70% of this heat is sensible heat that raises the temperature of the store, therefore, the contribution of people to the cooling load of the store = 70% of 28175 W

==> 0.7 x 28175 = <em>19722.5 W</em>

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From the calculations, the power expended is 43650 W.

<h3>What is the power expended?</h3>

Now we can find the acceleration from;

v = u + at

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v =  95 km/h or 26.4 m/s

t =  6.8 s

a = ?

Now

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a = 26.4 m/s/ 6.8 s

a = 3.88 m/s^2

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s = (26.4)^2/2 * 3.88

s = 696.96/7.76

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Now;

Work = Fs

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2 years ago
Find the mass of a sample of water if its temperature dropped 24.8 °C when it lost 870 J of
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8.35 × 10^{-3} kg

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Estimate the power you produce in running up a flight of stairs. Give your answer in horsepower (1 hp = 746 W). Suppose you clim
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The first thing you should do is calculate the work done when climbing the stairs. This work by definition will be given by:
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3 years ago
Read 2 more answers
A 70 kg base runner begins his slide into second base while moving at a speed of 4.35 m/s. He slides so that his speed is zero j
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Answer

given,

Mass of the runner, M = 70 Kg

speed of the runner on the second base = 4.35 m/s

speed at the base = 0 m/s

Acceleration due to gravity,g = 9.8 m/s²

a) magnitude of mechanical energy lost

  Mechanical energy lost is equal top gain in kinetic energy

   ME_{Lost}=\dfrac{1}{2}mv^2

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b) Work done = Force x displacement

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Work done is equal to 662.29 J

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using the coefficient of the friction,μ = 0.7

  x=\dfrac{662.29}{ 0.7\times 70\times 9.8}

     x = 1.38 m

Hence, the runner will slide to 1.38 m.

3 0
3 years ago
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