← Back to the activity

Class 4 The World Around Us — How things work

Work out what makes one thing spin and another wobble, run a float-and-sink test properly, and see why the same piece of foil can do both.

Name: ________________________

Before you start

The same square of aluminium foil, three times over, in three different shapes.

123
  1. 1. Spread out flat
  2. 2. Folded into a cup
  3. 3. Pressed into a ball

Nothing has been added and nothing taken away — it is one piece of foil, weighing the same in each of the three pictures. The shape is the single thing that changes between them, and the water does not treat the three the same way.

  1. 1.Meera and Dhruv spun these three. Sort them by what happened.

    Groups: Spins · Does not spin properly

    • Coin
    • Eraser
    • Bangle

  2. 2.The worked row of the float-and-sink table is a leaf. What reason does it record?

    • a) It is light
    • b) It is flat
    • c) It is green
    • d) It is dry

  3. 3.What does the chapter say about the lattu, a popular Indian spinning top?

    • a) It is commonly made of wood, though tops were made of clay in earlier times
    • b) It is a modern toy, made of plastic
    • c) It is made of iron so that it spins for longer
    • d) It is still made of clay, as it was thousands of years ago

  4. 4.Who does the chapter say used the charkha to make handmade clothes?

    • a) Jawaharlal Nehru
    • b) Rabindranath Tagore
    • c) Mahatma Gandhi
    • d) Sardar Patel

  5. 5.Which two everyday things does the chapter give as examples of things around us that spin?

    • a) Kites and paper planes
    • b) Ceiling fans and potters' wheels
    • c) Windows and doors
    • d) Bicycles and clocks

  6. 6.One piece of aluminium foil, three shapes. Sort each shape by what it did in the water.

    Groups: Floats · Sinks

    • Aluminium foil spread out flat
    • Aluminium foil in a cup-like shape
    • Aluminium foil pressed into a ball

  7. 7.In the float-and-sink activity, what happened to the iron nail and the leaf?

    • a) Both sank to the bottom
    • b) Both stayed on the surface
    • c) The nail sank and the leaf floated
    • d) The nail floated and the leaf sank

  8. 8.Two card spinners, each on a toothpick. One of them looks the same whichever side you view it from, stays upright and spins. Tap that one.

    Write the number of the part.

    12

Answer key — Class 4 The World Around Us — How things work

  1. 1. Coin → Spins; Bangle → Spins; Eraser → Does not spin properly
  2. 2. a) It is light
  3. 3. a) It is commonly made of wood, though tops were made of clay in earlier times
  4. 4. c) Mahatma Gandhi
  5. 5. b) Ceiling fans and potters' wheels
  6. 6. Aluminium foil spread out flat → Floats; Aluminium foil in a cup-like shape → Floats; Aluminium foil pressed into a ball → Sinks
  7. 7. c) The nail sank and the leaf floated
  8. 8. 1 — The left spinner