OBJECTS fell because the mass of the Earth attracts them .The force that pulls us towards the center of the Earth is known as gravitation.It keeps us on the ground and the satellites in their orbits.This force of attraction is much less on the moon than on the Earth - only one sixth .For this reason astronauts bounce when they walk on the moon because they experience weightlessness.In the state of weightlessness we do not feel any force of gravity and do not feel any weight .But we feel the force acting on us on the Earth,when we fall from a height or when we are thrown forward when brakes are applied.
MASS,WEIGHT,AND DENSITY.-All objects have mass.Because of the force of attraction on the Earth,an object has weight .This is the force with which , the body -is attracted .The force of gravity on the moon is just one sixth of that of the Earth..A person who weigh 60 kg on the Earth weigh only 10 kg on the moon.
The density of an object is the 'mass per unit volume,i.e,space occupied by one k.g of a substance.Because of the difference in their densities 1k.g of iron fits in a small cube ,and 1k.g of feathers fills a cupboard completely.
DUE TO THE GRAVITATIONAL ATTRACTION OF THE EARTH- Satellites don't fall to the Earth .At the same time they tend to 'fly' away from the Earth owing to its inertia.Finally ,they are short off from the Earth with a large force .If this initial thrust is measured properly while launching the rocket ,the satellite continues to move in an orbit around the Earth at the calculated speed.
WEIGHTLESSNESS- The phenomenon of weightlessness occur s when when the bodies do not feel any gravity .Gravity is the force with which the Earth pulls us towards its centre .We also feel weightless in free fall.Moreover , when two bodies are flying parallel to each other in the same gravitational field ,they are weightless.For example international space station (ISS) has been orbiting in the gravitational field of the Earth.Because of weightlessness equipment s that normally function with the help of gravity do not work..Therefore toilets are equipped with suction device , and one uses straw instead of cups to drink.
A long stay in weightlessness can lead to weakness.since there are no forces acting on bones and muscles in space .these are hardly used and degenerate.
MASS,WEIGHT,AND DENSITY.-All objects have mass.Because of the force of attraction on the Earth,an object has weight .This is the force with which , the body -is attracted .The force of gravity on the moon is just one sixth of that of the Earth..A person who weigh 60 kg on the Earth weigh only 10 kg on the moon.
The density of an object is the 'mass per unit volume,i.e,space occupied by one k.g of a substance.Because of the difference in their densities 1k.g of iron fits in a small cube ,and 1k.g of feathers fills a cupboard completely.
DUE TO THE GRAVITATIONAL ATTRACTION OF THE EARTH- Satellites don't fall to the Earth .At the same time they tend to 'fly' away from the Earth owing to its inertia.Finally ,they are short off from the Earth with a large force .If this initial thrust is measured properly while launching the rocket ,the satellite continues to move in an orbit around the Earth at the calculated speed.
WEIGHTLESSNESS- The phenomenon of weightlessness occur s when when the bodies do not feel any gravity .Gravity is the force with which the Earth pulls us towards its centre .We also feel weightless in free fall.Moreover , when two bodies are flying parallel to each other in the same gravitational field ,they are weightless.For example international space station (ISS) has been orbiting in the gravitational field of the Earth.Because of weightlessness equipment s that normally function with the help of gravity do not work..Therefore toilets are equipped with suction device , and one uses straw instead of cups to drink.
A long stay in weightlessness can lead to weakness.since there are no forces acting on bones and muscles in space .these are hardly used and degenerate.
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