How much energy (in joules) is used by a 1.0-hp motor that runs for 1.0 hour?
Complete Question:
How much energy (in joules) is used by a 1.0-hp motor that runs for 1.0 hour? (1 hp = 746 W)
a. 4.8J
b. 4.5 x 10⁴J
c. 2.7 x 10⁶J
d. 3.6 x 10³J
Answer:
The amount of energy used by a 1.0-hp motor that runs for 1.0 hour is 2.7 x 10⁶ J. Therefore, the correct option is C.
To calculate the amount of energy used by a 1.0-hp motor that runs for 1.0 hour, we can follow these steps:
- Convert horsepower (hp) to watts (W). Given that 1 hp = 746 W, a 1.0-hp motor has a power output of 1.0 * 746 W = 746 W.
- Calculate the energy used in watt-hours (Wh). Since the motor runs for 1.0 hour, the energy used in watt-hours is 746 W * 1.0 hour = 746 Wh.
- Convert watt-hours to joules (J). There are 3,600 seconds in 1 hour. Since 1 W = 1 J/s, we can convert the energy used in watt-hours to joules by multiplying the watt-hours by the number of seconds in an hour.
Energy in joules = 746 Wh x 3,600 seconds = 2,685,600 J
So, the amount of energy used by a 1.0-hp motor that runs for 1.0 hour is 2.7 x 10⁶ J (option c).