Question

A Ford Focus produces 160 horsepower \([16] . \quad\) Calculate the power produced in watts, and calculate the approximate energy produced by the vehicle in one hour.

Short answer

The Ford Focus produces 119312 watts and approximately 119312 watt-hours of energy in one hour.

Step-by-step solution

Convert Horsepower to Watts

To convert power from horsepower ( ext{hp}) to watts ( ext{W}), we use the conversion factor: \( 1 ext{ hp} = 745.7 ext{ W} \). So if a Ford Focus produces 160 horsepower, the power in watts is calculated as follows: \( 160 ext{ hp} \times 745.7 \text{ W/hp} = 119312 ext{ W} \).

Calculate Energy Produced in One Hour

Power is the rate at which energy is used over time. Therefore, to calculate energy produced in an hour, use the formula: \( ext{Energy} = ext{Power} \times ext{Time} \). The time period considered is one hour, which is equivalent to 3600 seconds since \( 1 ext{ hour} = 3600 ext{ seconds} \). Therefore, the energy produced in watts-hour is \( 119312 ext{ W} \times 1 ext{ hour} = 119312 ext{ Wh} \) or \( 119312 ext{ W} \times 3600 ext{ s} = 429523200 ext{ J} \) if calculated in joules.

Key concepts

Horsepower to Watts

When we think about a car's engine power, it's often measured in horsepower (hp). But to use this measurement in calculations, we typically need to convert it to watts (W), a more universal unit in the metric system. One horsepower is equivalent to 745.7 watts. This conversion factor helps translate the mechanical power produced into a unit of electrical power, which is easier to work with in calculations.
For instance, if a Ford Focus is said to produce 160 hp, converting this to watts involves simply multiplying:

• Power in watts = Horsepower × Conversion factor
• Power in watts = 160 hp × 745.7 W/hp
• Power in watts = 119,312 W

This conversion is crucial for any further calculations involving energy and power efficiency.

Energy Calculation

Energy is the capacity to do work, and it's intricately tied to power—the rate at which energy is used or produced over time. The calculation of energy depends on both power and the duration of time it is applied.
When a rate of 119,312 watts is applied for one hour, the energy produced can be calculated using the formula:

• Energy = Power × Time
• Energy = 119,312 W × 1 hour
• Energy = 119,312 watt-hours (Wh) or if we convert to joules,
• Energy = 119,312 W × 3600 seconds = 429,523,200 joules (J)

Thus, by simply multiplying the power in watts by the time in seconds or hours, we can determine the energy produced within that certain time frame.

Physics Education

Understanding the relationship between units like horsepower, watts, and energy is a fundamental aspect of physics education. Physics often breaks down complex systems into simpler, quantifiable processes. This helps develop a student's ability to transition between different units and measurements through conversions, a critical skill in scientific calculations.
Learning about power and energy in this context not only enhances comprehension of how engines work, but also offers insight into efficiency. It builds a tangible connection between theoretical knowledge and real-world applications. When students practice converting and calculating these values, they solidify their understanding of key physics principles and see the practical implications of what might otherwise seem abstract.
A clear grasp of such concepts equips students to tackle more complex global energy issues, fostering critical thinking and innovation in fields like automotive engineering, renewable energy, and technology.