Class 6 Science Chapter 7 Question Answers - Motion and Measurement of Distances

Short Answer Questions

Q1: What is the SI unit for measuring mass?
Ans: The SI unit for measuring mass is the kilogram (kg).

Q2: Give an example of an object in translatory motion.
Ans: A car moving on a straight road is an example of translatory motion.

Q3: What is the SI unit for measuring length?
Ans: The SI unit for measuring length is the meter (m).

Q4: Explain rectilinear motion with an example.
Ans: Rectilinear motion is when an object moves along a straight path. An example is a sprinter running in a 100-meter race on a straight track.

Q5: What is the difference between circular motion and oscillatory motion?
Ans: Circular motion involves an object moving in a circular path around a fixed point, like the blades of a fan. Oscillatory motion is when an object moves to-and-fro between two points, like a pendulum swinging back and forth.

Long Answer Questions

Q1: Why are accurate measurements important in our daily lives?
Ans: Accurate measurements are crucial because they help us measure time, distance, mass, volume, and temperature accurately. They are essential for creating things like classroom doors and windows and ensuring consistency in the products we use every day.

Q2: Explain the advantages of using SI units in measurements.
Ans: SI units, or International System of Units, provide consistency and uniformity in measurements worldwide. They make comparisons convenient and standardize products. For example, a bulb manufactured in any country using SI units will have the same size and performance characteristics.

Q3: Describe the different types of motion and provide an example of each.
Ans: There are various types of motion:

• Translatory motion: A car moving in a straight line.
• Circular motion: The hands of a clock moving in a circle.
• Rotational motion: The spinning blades of a fan.
• Periodic motion: The Earth's rotation and revolution.
• Oscillatory motion: The back-and-forth movement of a pendulum.
• Vibratory motion: The vibrating strings of musical instruments.

Q4: Explain the rules for writing SI units with examples.
Ans: There are four rules for writing SI units:

• Rule 1: The symbol of a measuring unit is written in small letters, except when named after a scientist. For example, "Joule" is written as "J" (for Joule).
• Rule 2: When the full form is used, the symbol is written in small letters, even if it's named after a scientist. For example, "joule" is written as "joule."
• Rule 3: Symbols for units are not written in plural, but full forms can be written in plural. For example, "The road is 10 m wide" or "The length of the pole is 1 m."
• Rule 4: Symbols are not written with a full stop unless they appear at the end of a sentence.

Q5: Discuss the significance of periodic motion in our daily lives and give examples.
Ans: Periodic motion is essential as it repeats itself in a fixed time interval, allowing us to measure time and track regular events. Examples include the hands of a clock (hour and minute hands), Earth's rotation, and the Earth's revolution around the sun. These motions help us keep time, establish calendars, and understand the changing seasons.