Chapter 1: Measurement

Question 1

What are physical quantities?

Answer 1

Physical quantities are measurable aspects of the physical world. They can be anything that can be measured, such as length, mass, time, temperature, and more.

Question 2

What are base quantities?

Answer 2

Base quantities are fundamental quantities that cannot be defined in terms of other quantities.
Length (meter, m)
Mass (kilogram, kg)
Time (second, s)
Thermodynamic Temperature (kelvin, K)
Electric Current (ampere, A)
Luminous Intensity (candela, cd)
Amount of Substance (mole, mol)

Question 3

What are derived quantities?

Answer 3

Derived quantities are quantities that are defined in terms of base quantities.
Area: Length x Length (m²)
Volume: Length x Length x Length (m³)
Speed: Distance / Time (m/s)
Acceleration: Change in Velocity / Time (m/s²)
Force: Mass x Acceleration (kg m/s²)

Question 4

What is the difference between scalar quantities and vector quantities?

Answer 4

Scalar quantities have magnitude only.
Examples:
Distance
Speed
Time
Mass
Temperature
Vector quantities have both magnitude and direction. Examples:
Displacement
Velocity
Acceleration
Force
Momentum

Question 5

What are the steps involved in a scientific investigation?

Answer 5

1.Observation: Carefully observe the phenomenon you are interested in.
2. Hypothesis: Formulate a testable explanation for the observation.
3. Experiment: Design and carry out an experiment to test your hypothesis.
4. Data Analysis: Analyze the data you collected from the experiment.
5. Conclusion: Draw a conclusion based on your data analysis. Does the data support your hypothesis?
6. Communication: Share your findings with others.

Question 6

How can we use graphs to represent data?

Answer 6

Graphs are a powerful tool for visualizing data and understanding relationships between variables.
Line Graphs: Show the relationship between two variables.
Bar Graphs: Compare data for different categories.
Pie Charts: Show the proportions of a whole.
Scatter Plots: Show the relationship between two variables, but without drawing a line connecting the points.

Question 7

What are some ways to analyze graphs?

Answer 7

Shape of the Graph: What does the overall shape of the graph tell you about the relationship between the variables?
Gradient: What is the slope of the line? What does it tell you about the relationship between the variables?
Intercept: Where does the line cross the y-axis? What does the y-intercept tell you?
Area Under the Graph: What does the area under the graph represent?