Important Questions for Class 7 Curiosity Chapter 8 Measurement of Time and Motion

Important Questions for Class 7  Curiosity Chapter 8 Measurement of Time and Motion

Short Question-Answers — 2 Marks Each

1. What is motion? Give one example.
Answer: Motion is the change in the position of an object with time. An object is said to be in motion when its position changes with respect to a reference point.
Example: A moving car is in motion.

2. What is periodic motion? Give two examples.
Answer: The motion that repeats itself after equal intervals of time is called periodic motion.
Examples:

1. Motion of a pendulum
2. Revolution of the Earth around the Sun

3. Differentiate between uniform and non-uniform motion.
Answer: In uniform motion, an object covers equal distances in equal intervals of time. In non-uniform motion, an object covers unequal distances in equal intervals of time. A train moving at a constant speed shows uniform motion, while a bus moving through traffic generally shows non-uniform motion.

4. What is speed? Write its formula and SI unit.
Answer: Speed is the distance travelled by an object in unit time. It tells us how fast an object is moving.
Formula: Speed = Distance ÷ Time
SI unit: metre per second (m/s)

5. Why is a standard unit of time necessary?
Answer: A standard unit of time is necessary so that time measurements can be compared accurately everywhere. The second (s) is the SI unit of time. Using standard units avoids confusion and ensures that measurements made by different people are consistent.