# ANYONE ANSWER THIS QUESTION PLEASE! It's about energy, work and power. Having a hard time trying to solve this?

1. A motor does 5,000 joules of work in 20 seconds. What is the power of the motor?

2. A machine does 1,500 joules in work in 30 seconds. What is the power of this machine?

3. A hairdryer uses 72,000 joules of energy in 60 seconds. What is the power of this hairdryer?

4. A toaster oven uses 67,500 joules of energy in 45 seconds to toast a piece of bread. What is the power of the oven?

5. A horse moves a sleigh 1.00 kilometer by applying a horizontal 2,000-newton force on its harness for 45 minutes. What is the power of horse? ( Hint: Convert time to seconds )

6. A wagon is pulled at a speed of 0.40 meters/sec by a horse exerting an 1,800-newton horizontal force. What is the power of this horse?

7. Suppose a force of 100 newtons is used to push an object a distance of 5 meters in 15 seconds. Find the work done and the power for this situation.

8. Emily’s vacuum cleaner has a power rating of 200 watts. If the vacuum cleaner does 360,000 joules of work, how long did Emily spend vacuuming?

9. Nicholas spends 20 minutes ironing shirts with his 1,800-watt iron. How many joules energy were used by the iron? (Hint: convert time to seconds).

10. It takes a clothes dryer 45 minutes to dry a load of towels. If the dryer uses 6,750,000 joules of energy to dry the towels, what is the power rating of the machine?

Relevance

1. Power is just the energy rate. So that would be 5000J/20s = 250W

2. Same. 1500J/30s = 50W

3. Same. 1200W or 1.2KW

4. 1500W or 1.5KW

5. Energy = F*d = 2000N * 1000m = 2000KJ

2000KJ/(45min*60) (convert to seconds) = 0.741KW or 741W

6. Same

7. Same

8. 200W = 360000/t ; t= 1800s

9. 1800W = E / 20 * 60 ; E = 2160000J or 2160KW

10. Same