A 2400W electric toaster is connected to a standard 120 V wall outlet. A family measured their monthly toaster usage to be 6.5 hrs.

1) How much electrical energy (in kilowatt hours - kWh) did the toaster dissipate

during the measured month? (round to 1 decimal place & do not include units)

2) If the local power company charges $0.13/ kWh, then calculate (in $) the monthly

total cost of this toaster. (round to 2 decimals & do not include units)

1)  energy = 15.6 kWh,  2)    total_cost = $ 2.03

Explanation:

1) The energy dissipated is the product of the power and the time of use In a month it was used t = 6.5 h and the power of the toaster is

P = 2400 W = 2,400 kW

       energy = P  t

       energy = 2,400  6.5

        energy = 15.6  kWh

using rounding to a decimal

        energy = 15.6 kWh

2) The cost of energy is unit_cost = $ 0.13 / kWh

so the total cost

         total_cost = energy    unit_cost

         total_cost = 15.6   0.13

         total_cost = $ 2.028  

rounding to two decimal places

         total_cost = $ 2.03

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2