Na certain city, electricity costs $0.18 per kw·h. what is the annual cost for electricity to power a lamp-post for 6.50 hours per day with (a) a 100.-watt incandescent light bulb (b) an energy efficient 25-watt fluorescent bulb that produces the same amount of light? assume 1 year = 365 days.

a)

Consumption of power in one day =

Consumption of power in one year =

Since, . So,

Given that =

So, for :

$ = $

Hence, the annual cost is $.

b)

Consumption of power in one day =

Consumption of power in one year =

Since, . So,

Given that =

So, for :

$ = $

Hence, the annual cost is $.

Explanation:

H₃O⁺ and H₂O .

H₂O + H⁺  ⇄   H₃O⁺

H₂O accepts proton to form H₃O⁺ so H₂O is base .

H₃O⁺  ⇄   H₂O + H⁺

Here H₃O⁺  is acid because it gives proton ( H⁺ ) .

HCO₃ ⁻ and H₂CO₃

H₂CO₃  ⇄   HCO₃ ⁻ + H⁺

H₂CO₃ is acid because it gives proton ( H⁺ )

HCO₃ ⁻ + H⁺ = H₂CO₃

HCO₃ ⁻  is base because it accepts proton .