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madreJ [45]
4 years ago
14

Calculate the payback time if she insulates the loft with 300 mm insulation when: area of loft space = 100m^2 cost of roll of 10

0 mm thick loft insulation that covers 8.3m^2 = £20 cost of putting the insulation into the loft = £120 savings per year = £80 per 100 mm Payback Time = installation cost divided by annual savings
Chemistry
1 answer:
ycow [4]4 years ago
8 0

Answer: Payback time = 0.0075

Explanation: Since payback time is calculated as:

payback time = \frac{installation cost}{annual savings}

First determine the installation cost:

100 mm thick insulation covers 8.3 m². Then 300 mm covers 24.9 m².

To cover 8.3m² costs £20. Then, the cost to cover 24.9 m² is:

cost = \frac{20*24.9}{8.3}

cost = £60

The cost of putting the insulation is £120, so the total cost is:

total cost = £60 + £120

total cost = £180

Savings per year per 100 mm thick is £80. For 300 mm, the value of annual savings is:

savings = \frac{300*80}{100}

savings = 240

payback time = \frac{installation cost}{annual savings}

payback time = \frac{180}{240}

payback time = 0.75

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One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
MAXImum [283]

Answer:

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Explanation:

Let the metallic oxide be M₂O

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We assume Molar mass of M to be x.

We are told that 5.00 g of the metallic oxide produces 2.32 g of the metal.

By proportion, we can write the following;

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This cancels out to give us;

10/(2x + 16) = 2.32/x

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6 0
3 years ago
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