Units and physical quantities

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What is the primary purpose of using units?

To make calculations simpler

To compare different physical quantities

To define fundamental quantities

To express the numerical value of a physical quantity (correct)

What are the three fundamental physical quantities?

Time, velocity, and force

Length, time, and speed

Length, temperature, and mass

Length, time, and mass (correct)

How is the length of an object defined?

By calculating the object's mass

By measuring the object's time

By determining the object's velocity

By comparing the object with multiples of some standard length (correct)

What are meters, feet, seconds, and hours examples of?

Base units Signup and view all the answers

What are units of miles per hour, kilometers per hour, and meters per second examples of?

Derived units Signup and view all the answers

What is the purpose of using standard units of time?

To measure the time of an event Signup and view all the answers

What is the unit used to measure the mass of an object?

Kilograms Signup and view all the answers

What is the result of converting units?

An expression of the same physical quantity in different units Signup and view all the answers

What is the primary base unit for measuring time?

Second Signup and view all the answers

What does the prefix 'centi-' represent in a unit?

A factor of 10^(-2) Signup and view all the answers

What is the purpose of using conversion factors?

To convert units from one system to another Signup and view all the answers

How are units treated in calculations?

As algebraic quantities Signup and view all the answers

What is the conversion factor for 1 mile in meters?

1 mile = 1609 meters Signup and view all the answers

What is the primary unit for a given fundamental quantity?

The unit that is designated as primary Signup and view all the answers

What is the purpose of using powers of ten in units?

To make units more convenient to use Signup and view all the answers

What is the result of carrying units along in a calculation?

Both the numerical answer and the correct units are obtained Signup and view all the answers

What is the primary purpose of using units in measurements?

To identify common errors in measurements Signup and view all the answers

When expressing a measurement with uncertainty, what does the ∓ symbol indicate?

A range of possible values Signup and view all the answers

Which of the following digits are always significant?

Only non-zero digits Signup and view all the answers

What is the rule for trailing zeros in a number without a decimal place?

They are never significant Signup and view all the answers

When multiplying or dividing numbers with different numbers of significant figures, what is the rule for the final answer?

The final answer should have the same number of significant figures as the number with the least Signup and view all the answers

What is the purpose of specifying the uncertainty in a measurement?

To provide a range of possible values Signup and view all the answers

What is the significance of leading zeros in a number?

They are never significant Signup and view all the answers

What is the rule for significant figures when adding or subtracting numbers with different numbers of significant figures?

The final answer should have the same number of significant figures as the number with the least Signup and view all the answers

Why is it important to specify the units of a measurement?

To provide a sense of the magnitude of the measurement Signup and view all the answers