Force

FORCE

•      A push or pull acting on an object is called force.

•      Force make things move or make things change their motion.

(a)                                (b)

Figure 1: (a) A weightlifter is lifting (pulling) the weight

(b) A soldier is firing bullet from a machine gun

•      Two natural forces that affect most of the motion we are aware of are the force of gravity and electromagnetic forces.

•      Gravity is one of the universal forces of nature. It is the force of attraction by which terrestrial bodies tend to fall towards the center of the earth.

•      It is an attractive force between all matters, and is very weak as compared to the other forces of nature.

•      Magnetism is the force that causes a nail or paper clip to be pulled towards a magnet. It is the force of attraction or repulsion between two magnets.

•      A force can change the original shape and size of a body.

For example:

Figure 2: A teacher pulls down a projector, A blue hat boy pushing a red hat boy, a huge bus is pulling three cars

A chariot is pulled by a horse, A little girl is trying to open an almira by pulling its door

Figure 3: A girl is pushing the toys and trying to keep all the toys in a large red bag, A puppy is playing with a ball by pushing it again and again

An old man is pushing a machine, a boy is pulling a small cart with another boy, A woman is pulling a wagon

Figure 4: Two naughty children are pulling their mom from both the sides; a father is applying force (pushing) on the swing so that his daughter can enjoy swinging

A girl is pushing a wheelchair with a patient on it, A girl is pulling a carriage

Figure 5: A boy and an old man is pushing a pencil (applying force on the pencil) to write something on the paper

•      Even we might list a door that needs to be pushed to open, a box with a top that needs to be pulled off, or a pencil, which requires both a push and a pull.

Figure 6: A boy is pushing a toy car and trying to resist its speed with other toy car, A boy is pushing a toy car

More about push and pull:

•      Force is a push or pull that can change an object's position, and put it in motion.

•      A person might pull a door to open it, or push a door to close it.

•      A person might pull a shopping cart, pull a wagon behind him/her, pull someone on the swings, pull flowers to pick them, etc.

Figure 7: A woman is pulling a fishing rod to grab a fish, A boy is trying hard to pull a huge red bag

An old man is pulling a machine; A black clothed man is pulling a heavy object

Figure 8: Many animals tied together are pulling a cart; a man is pulling a paddle rickshaw

A little girl is pulling a door of a cupboard; a boy is trying to get his book by pulling it from the mouth of his pet dog

Figure 9: A boy is pulling the rope tied to the horse, A material is pulled by two persons from both sides, A man is pulling out some material from a sofa, A lady is pulling the rope tied to a bell, A person is trying to pull up the other person

POINTS TO REMEMBER

A force on an object does not always cause it to move.

For example:

1. Pushing against a wall does not cause the wall to move.
2. The ring around the press button supports the button but if we try to press the ring, it will not cause any movement but if we apply force on the button, it will show movement.