A central air-conditioner uses 3500W of electricity. If electricity costs $0.087/kW*h. calculate how much it would cost to operate the air-conditioner 24 hours a day for 4 months (120 days).

$876.96

Explanation:

The energy used is:

3500 W × (24 hr/day) × (120 day) × (1 kW / 1000 W) = 10,080 kWh.

So the cost is:

10,080 kWh × ($0.087 / kWh) = $876.96

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

prolly a beacuse the momentuem the car has increases while going down hill