Question

A PS4 uses 8.8 watts when on stand-by mode.

a) How much electricity would be used if you have your PS4 on stand-by 21 hours a day for 1 week?
Express your answer rounded to the nearest hundredth of a kilowatt-hour.

1.29 kW-hr

b) How much carbon dioxide is emitted into the atmosphere to produce this electricity?
Express your answer rounded to the nearest tenth of a pound of carbon dioxide.

Answer 1

a) Electricity = 1.29 kWh

b) Carbon dioxide = 1.4 pounds

Explanation:

Given : A PS4 uses 8.8 watts when on stand-by mode.

a) To find how much electricity would be used if you have your PS4 on stand-by 21 hours a day for 1 week

In 1 day PS4 is on standby = 21 hours

1 week = 7 days

In 7 days PS4 is on standby = 21 × 7 = 147 hr in a week

PS4 uses 8.8 watts

For 147 hr PS4 uses = 8.8 × 147 = 1293.6 watt-hour

To convert into kilowatt-hour divide watt-hour by 1000

In kW-hr =
`(1293.6)/(1000)=1.2936 \text{kW-hr}`

Rounded to nearest hundredth electricity used = 1.29 kW-hr

b) How much carbon dioxide is emitted into the atmosphere to produce this electricity

1 kWh of electricity = 500 g of
`CO_2`

In 1.29 kWh of electricity = 1.29 × 500 =645 gram of
`CO_2`

Now, 1 gram = 0.00220462 pounds

645 gram = 1.42 pounds

Nearest tenth = 1.4 pounds

Answer 2

a. total power usage PS4 in a week = 8.8 watts x 21 hrs/day x 7 days/week
= (1293.6 watt.hr/week) / (1 kW/1000w)
= 1.29 KW hr/ week
b. carbon emission = 2.1lb/KW
= 1.29 KW x 2.1lb/KW
= 2.71 lb