Gravitation And Weightlessness JSS1 Basic Science Lesson Note

GRAVITATION AND WEIGHTLESSNESS

v Meaning

v Effect

 Meaning

GRAVITATION

Gravitation is a force that affects the stability of a body.

If an object is tossed up in the air, it will fall back to the ground because the earth exerts an attraction on it. This attraction is called gravitational attraction.

The gravitational attraction/force between any two objects increases as the two objects approach each other.

The earth has a great gravitational full because it has a great mass. The gravitation pull of the earth is always directed to the center.

WEIGHTLESSNESS

Weightlessness is a feeling of being weightless. It does not mean having no weight. As someone moves away from the surface the progressively reduces. On the outer surface of the earth, a person or body does not weigh because the gravitational pull of the earth is no longer acting there.

Effect of gravitation on objects

1.     Stability of the earth:  Gravitation helps every object on the earth including man     to remain stable
2.     Weight: The weight of an individual is a measure of the gravitational pull of the earth on that person
3.     Revolution of the moon around the Earth: The moon can revolve around the Earth because the gravitational pull of the Earth attracts it
4.     Balance of planets in our solar system: The sun and all the planets in our solar system exercise gravitational pulls on one another and mutually balance one another in space
5.     Work is done against gravity in lifting an object from the earth: Lifting an object from the ground involves opposing gravitational pull, therefore work is done against gravitational attraction of the earth

CLASSWORK 6

1.     Define gravitational pull
2.     What is weightlessness?