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Frictional Force

Force of friction acts on the moving objects and its direction is opposite
to the direction of the motion. The force of friction arises because of
Science contact between surfaces.
Bytes
Mechanical Force
Testimony
Magne c fields of Earth In some cases, machines are used to generate force. These machines
make compass needles a utilise the human muscular force to generate force. The force
high north-south – a
principle used in so generated is called mechanical force . In simple terms, mechanical
naviga on fro centuries. force is the force generated by machines. Some examples are forces

generated by screwdriver, stapler, rail engine, etc.

2. Non-Contact Force
This type of force arises when objects are not in physical contact with
each other. The force acts on the objects from a distance.

Some non-contact forces are :

• Gravitational Force • Magnetic force
• Electrostatic force

Gravitational Force

The force exerted by the Earth on all objects is called gravitational force .
It is by this force that all bodies are attracted towards the Earth.

This force acts as a distance force as all objects are not necessarily in
contact with the Earth.

The gravitational force exerted by the Earth opposes the upward
movement of an object. Due to this pull, the speed of the object
decreases and becomes zero. The force of the Earth which is still acting on
it, pulls the body and it falls down.

When a stone is tied to a rubber band and held in the hand in such a way
that it hangs freely, the rubber band stretches and we say that the

weight of the stone is more. The weight of an object is thus the measure
of the force with which the object is pulled towards it.
Gravitational Force

(Weight = Mass × Gravity)
Weight on Different Planets

The weight of an object depends on the gravitational pull of the planet
on which it is located. Since the strength of gravity is different on each

planet, the same object will weigh differently. For example, a person
weighing 60 kg on Earth would weigh only about 10 kg on the Moon

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