Question

State the basic metric system unit for each of the following physical quantities. (a) length (b) mass (c) volume (d) time (e) temperature (f) heat energy

Short answer

(a) meter; (b) kilogram; (c) liter; (d) second; (e) degrees Celsius; (f) joule.

Step-by-step solution

Determining the Unit for Length

The basic metric unit for measuring length is the **meter**. It is commonly represented by the symbol \(m\).

Identifying the Unit for Mass

The standard metric unit for mass is the **kilogram**. The kilogram is denoted by the symbol \(kg\).

Choosing the Unit for Volume

Volume in the metric system is typically measured in **liters**. The liter is often represented by the symbol \(L\).

Recognizing the Unit for Time

The basic metric unit for measuring time is the **second**. This is expressed with the symbol \(s\).

Selecting the Unit for Temperature

Temperature in the metric system is measured using **degrees Celsius**. This unit is represented by the symbol \(°C\).

Specifying the Unit for Heat Energy

The basic unit for heat energy in the metric system is the **joule**. It is represented by the symbol \(J\).

Key concepts

Length Measurement

In the metric system, the base unit for measuring length is the meter, symbolized as \( m \). It's a fundamental measure that helps describe how long or wide things are. We use it in various applications, from measuring the height of a building to the length of a road.

It's important because it serves as a basis for other derived units like kilometers for larger distances and centimeters or millimeters for smaller lengths. The meter allows us to have a universal standard against which we can measure all kinds of lengths easily.

• 1 kilometer = 1000 meters
• 1 meter = 100 centimeters
• 1 centimeter = 10 millimeters

Mass Measurement

Mass is measured using the kilogram in the metric system, which is abbreviated as \( kg \). This unit is crucial for describing how much matter is in an object. While the kilogram is the standard, other units like grams and milligrams are also used for different levels of precision.

When we weigh something, we're measuring mass, and the standardization to kilograms helps ensure consistency across different systems and scales.

• 1 kilogram = 1000 grams
• 1 gram = 1000 milligrams
• Measurements of large-scale masses often use metric tonnes, where 1 tonne = 1000 kg

Volume Measurement

Volume is typically measured in liters, denoted by the symbol \( L \). This unit tells us how much space an object or substance occupies. It's especially handy for liquids like water or juice but is equally applicable to gases and even solids when needed.

Understanding volume is essential as it helps in activities such as cooking, where precise measurements of liquids are crucial, or in scientific experiments, where volume can affect reactions.

• 1 liter = 1000 milliliters
• For larger volumes, kiloliters are used, where 1 kiloliter = 1000 liters
• For smaller volumes, milliliters are practical, such as in medicine

Temperature Measurement

Temperature in the metric system is measured in degrees Celsius, represented as \( °C \). This scale sets the freezing point of water at 0°C and the boiling point at 100°C under normal atmospheric pressure.

Celsius is widely used in most countries around the world because it makes scientific temperature measurement intuitive and straightforward.

• Water freezes at 0°C
• Water boils at 100°C
• Other scales, like Kelvin, are used in scientific research for more precision

Time Measurement

Time is universally measured in seconds, expressed as \( s \). This base unit is crucial for all kinds of time-related activities, from timing a race to scheduling events.

In the metric system, seconds are the fundamental unit, but minutes and hours are also commonly employed. These provide a seamless transition between day-to-day time representation and precise scientific measurement.

• 1 minute = 60 seconds
• 1 hour = 3600 seconds (or 60 minutes)
• Milliseconds and microseconds are used for very precise time measurements

Heat Energy Measurement

Heat energy in the metric system is measured in joules, represented by \( J \). This unit measures the amount of energy transferred or transformed. The joule is a versatile unit that's not only used for heat energy but also in physics to express energy in general.

Understanding joules helps us comprehend processes where energy conversion takes place, like in engines or in food calorie calculations.

• 1 joule = 1 Newton-meter
• 4,184 joules = 1 dietary Calorie
• In physics, joules are used to calculate kinetic and potential energy