• A Measuring wooden scale

• Earth tries to pull every object towards it. This is called gravitational force. An external force is needed to move any object away from the earth. When we are lifting objects, say a box, then we apply a force to lift it against the gravitational force.
• If any object is ped, then it falls down due to the gravitational force which pulls the objects towards the earth.
• Any object can be balanced on a single point, if we know the point called the centre of gravity.
• Ask the child whether she can balance a scale with her index finger.
• If it is not possible with one finger, ask her to do with index finger of both hands.
• Simple way to find the centre of gravity is keep left index finger on the left corner of the scale. Right index finger on the right corner of the scale.
•  Now move both the fingers with equal speed until bothe the fingers touch each other. Now the scale must be balanced. So the centre of gravity falls between the two fingers.

Moon also has gravitational force. But space does not have any gravitational force , only because of this astronauts floats in the space.

Every astro objects has gravitational force to pull the objects towards it. The force various as the size of the astro object varies.

• Sun supplies heat and light to the earth.
• Day and night cycle of earth.