University:
Campbell University
Course:
PHYS 252 | Fundamentals of Physics II
Academic year:

2023
Views:

217

Pages:

2
Author:

nismChiehearijzf

**Joule's Law** 1) Your oven has a power rating of 5000 W. a. How many kilowatts is this? 5000 W × 1 kW/1000 W = 5 kW b. If the oven is used for two hours to bake cookies, how many kilowatt-hours (kWh) are used? 5 × 2 = 10 kWh c. If your town charges $0.15 per kWh, what is the cost to use the oven to bake the cookies? 10 kWh × $0.15/kWh = $1.50 2) You use a 1200 W hair dryer for ten minutes each day. a. How many minutes do you use the hair dryer in a month? (Assume 30 days in the month.) 10 × 30 = 300 min 300 min × 1 h/60 min = 5 hours b. How many hours do you use the hair dryer in a month? 5 hours c. What is the power of the hair dryer in kilowatts? 1200 W × 1 kW/1000 W = 1.2 kW d. How many kilowatt-hours of electricity does the hair dryer use in a month? 1.2 × 5 = 6 kWh e. If your town charges $0.15 per kWh, what is the cost to use the hair dryer for a month? 6 × 0.15 = $0.90 F) Given the power of the heater is 1500 W. The heater was used for three hours. 1500 W × 1 kW/1000 W = 1.5 kW 1.5 × 3 = 4.5 kWh 4.5 × 30 = 135 kWh × $0.15 = $20.25 3. Calculate the power rating of a home appliance (in kilowatts) that uses 8.0 A of current when plugged into a 110 V outlet. P = VI P = (8.0)(110) P = 880 W 880 W * 1 kW / 1000 W = 0.88 kW 4. Calculate the power of a motor that draws a current of 2.0 A when connected to a 12 V battery. P = VI P = 12 * 2.0 P = 24 W 5. Your alarm clock is connected to a 110 V circuit and draws 0.50 A of current. a. Calculate the power of the alarm clock in Watts. P = VI P = (110)(0.50) P = 55 W b. Convert the power to kilowatts. 55 W × 1 kW / 1000 W = 0.055 kW c. Calculate the number of kilowatt-hours of electricity used by the alarm clock if it is left on for one year. 0.055 kW * 24 h * 365.25 day = 482 kWh d. Calculate the cost of using the alarm clock for one year if your town charges $0.15 per kWh. 482 kWh * $0.15 / kWh = $72.30

1.5KW to Watts

Related Documents

Recommended Documents

Description

Related Documents

Free up your schedule!

Take 5 seconds to unlock