I need some help with these problems How many watts does a flashlight that has 6
ID: 1878583 • Letter: I
Question
I need some help with these problems
How many watts does a flashlight that has 612 C pass through it in 0.41 h use if its voltage is 2.6 V? DQuestion 12 2 pts An electric water heater consumes 6.9 kW for 2.4 h per day. What is the cost in dollars) of running it for one year if electricity costs 14.2 cents/kW·h? D Question 13 2 pts Find the power dissipated in an extension cord having a 0.062 resistance and through which 5.79 A is flowing. D Question 14 2 pts With a 1275 w toaster, how much does it cost (in cents) to make a slice of toast if the cooking time is 0.9 minutes? Assume the rate is 10.9 cents/kW·h DQuestion 15 2 pts What is the current in milliamperes produced by the solar cells of a pocket calculator through which 2.52 C of charge passes in 7 h?Explanation / Answer
11)Given,
Q = 612 C ; t = 0.41 h = 1476 s ; V = 2.6 V
I = Q/t = 612/1476 = 0.41 A
P = VI = 2.6 x 0.41 = 1.07 W
Hence, P = 1.07 W
12)P = 6900 W ; t = 2.4 h = 8640 s
Power in KWh will be:
P(kWh) = 6900 x 2.4/1000 = 16.56 KW-h
for 1 kW-h cost is 14.2 cents
for 16.56 KW-h, Cost = 16.56 x 14.2 = 235.15 cents
In Dollars, cost = 2.35 dollars
13)R = 0.062 Ohm ; I = 5.79 A
P = I^2 R = 5.79^2 x 0.062 = 2.08 W
Hence, P = 2.08 W