• A push or pull acting on an object is called force.
• Force make things move or make things change their motion.
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.
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.