Question

Collect a few items of different shapes, such as metre scale, broom, ball, stick, paper cutouts of different shapes and so on. Try to balance these items and use the concepts learned in the chapter to find out their centre of gravity.

Answer 1

Aim: To find the centre of gravity of different objects by balancing them.

Materials Required: Metre scale, broom, ball, stick, paper cutouts of different shapes, etc.

Procedure:

• Collect objects of different shapes and sizes.
• Try to balance each object on a finger or a pointed support.
• Observe the point where the object balances without falling.
• Mark that point as the approximate centre of gravity of the object.
• Compare the positions of the centre of gravity for different shapes.

Observation Table:

Object	Shape	Method of Finding Centre of Gravity	Position of Centre of Gravity
Metre scale	Rectangular	Balanced at the midpoint	At the centre of the scale (50 cm mark)
Broom	Long and uneven	Balanced by placing finger below it	Near the heavier end
Ball	Spherical	Balanced from any direction	At the centre of the ball
Stick	Long and uniform	Balanced at the midpoint	At the centre of the stick
Circular paper cutout	Circular	Balanced at different points	At the centre of the circle
Triangular paper cutout	Triangle	Balanced using symmetry	At the intersection point of medians

Conclusion: The centre of gravity is the point where the entire weight of an object appears to act. For symmetrical objects, it lies at the geometrical centre, while for irregular objects, it can be found by balancing the object. The stability of an object depends on the position of its centre of gravity.