Class 4 EVS Chapter 7 How Things Work helps students understand how everyday things work through simple experiments and observations. It builds curiosity and encourages learning by doing. Students learn that science is all around us and can be explored through fun activities.
Every day, we use many objects like toys, books, bags, and tools. But have you ever wondered how these things work?
How Things Work Worksheet
Our worksheets are carefully created in line with the latest curriculum standards, helping students build a strong understanding of concepts and prepare confidently for their exams. Students can also download Class 4 EVS NCERT Solutions for accurate and easy-to-understand textbook answers.
What Students Will Learn
- How and why some objects spin
- Factors affecting spinning (shape, balance, position)
- Difference between floating and sinking objects
- How shape and material affect floating
- Importance of observation and experimentation
- How to design simple objects like spinners and boats
Also Download:
Class 4 Hindi Worksheets
Class 4 EVS Worksheets
How Things Work Chapter Notes
Things Around Us
- We use many objects daily like pencils, bags, toys, etc.
- Each object works in a specific way.
- We can understand how things work by observing and experimenting.
Spinning Objects
- Some objects can spin (coin, bangle, top).
- Some objects do not spin properly (eraser, stone).
Observations:
- A spinning object slows down and starts shaking before stopping.
- Objects that are balanced and symmetrical spin better.
Key Concept:
- Balance and shape affect spinning.
- A spinner works best when its centre is properly aligned.
Making Spinners (Activity-Based Learning)
- Spinners can be made using cardboard and toothpicks.
- Different designs affect spinning.
Important Findings:
- Spinner with hole at centre → spins well
- Hole away from centre → does not spin properly
- Square shapes appear circular while spinning
Colours and Spinning
- When coloured spinners spin, colours may appear mixed.
- Shows how motion changes appearance.
Floating and Sinking
Basic Idea:
Some objects float, others sink in water.
Observations:
- Leaf → floats
- Iron nail → sinks
- Empty bottle → floats
- Filled bottle → may sink
Important Concept:
Floating or sinking does not depend only on weight.
- It depends on:
- Shape
- Material
- Air inside the object
Effect of Shape
Same material can float or sink depending on shape.
- Example:
- Aluminium foil:
- Spread out → floats
- Cup shape → floats
- Ball shape → sinks
So, shape plays a very important role.
Making Boats
Boats can be made using paper, sticks, coconut shells, etc.
- Good boats:
- Float well
- Stay balanced
- Do not flip
Improving Designs
- Strong boats → do not break easily
- Balanced boats → do not tip
- Design changes improve performance
Class 4 EVS Chapter 7 Question Answers
Q1. Explain how the position of the centre affects spinning.
Ans: When the hole of a spinner is at the centre, it spins evenly because all sides are balanced. If the hole is away from the centre, the spinner becomes unbalanced and does not spin properly.
Q2. Why do some objects float while others sink?
Ans: Objects float or sink based on their shape, material, and the amount of air inside them. Light objects usually float, but some heavy objects can also float if their shape allows them to hold air.
Q3. How does shape affect floating and sinking?
Ans: Shape changes how an object interacts with water. For example, aluminium foil floats when spread out but sinks when pressed into a ball. This shows that shape is important.
Q4. What happens when a spinner slows down?
Ans: It starts shaking and then stops.
Q5. Why do some boats flip?
Ans: Because of poor balance or shape.
Q6. What happens when colours are added to a spinner?
Ans: Colours appear mixed when it spins.
