What is a push and pull Force?

Summary

A force is a push or pull upon an object resulting in an interaction between the two objects. When there is an interaction, there is a force. Thus forces only exist when there is an interaction.

Objects have mass. A force of a push or pull will cause it to change velocity.

Video on Push and Pull

Sometimes objects don’t change direction or move. This is due to forces that are of equal size in opposite direction. This force is balanced and would not cause a movement. It is an unbalanced force that causes an object to move or change direction.

balanced force
An object is in a state of inertia, in a constant speed or velocity, unless disturbed by an external force.

Upthrust Force

Object on water experience a force that pushes an object up and makes it seem to lose weight in the fluid. Upthrust is also called buoyancy and it explains a boat floating on water or a swimmer moving in the water. Upthrust also occurs in air. A helium balloon floating in the air also experience the upthrust force.

There is a force in water, upthrust force, that allows the boat to float on water.

Use of Forces

Forces can be used to twist or turn objects.

There is a force that twists an object. This force and the twisted object is called torsion.
There is a force than turns or spins an object, which would move in a straight line. This force makes the earth move around the sun, because of the sun’s gravity.

Objects will spin quicker if the force is greater.

Activities

Synonyms for twist/turns, push and pull. Make a list of words that are the synonym for twists/turns, push and pull. Compare your answers. Click on the link below.

Make a list of things you can twists/turn. What happens to the objects that you can twist and turn.

Push and Pull. Look around your house and find items that would do a push and pull motion. Then sort the items according to push and pull. For example you may find elastic, puzzles, etc.

Types of Forces

Interactions between objects can occur on physical contact or as a result of non-physical contact between objects.

Pulling the horse forward involves physical contact between objects.
Pushing a cart involves physical contact.
Gravitation is a non-physical contact between objects.

Activity

Observe the Force. Create you own experiment to show how objects can move faster, come to a rest, or change direction.

Types of Forces that involves Physical Contact

Frictional force

A force that is exerted by a surface as an object moves across it or makes an effort to move across it.

A courier pushing a crate up a ramp into a delivery truck. There is a sliding friction when pushing a box across a floor surface offers resistance to the movement of the box. Thus, the floor exerts a friction force upon the box.
A bolt that is tightened so as it cannot loosen or fall out has a strong static friction.

Tension Force

A tension force is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends.

The construction crane hook and pulley under load.

Normal Force

Normal force is support force. It the force exerted upon an object that is in contact with another stable object.

The shelf support the weight of the books.

Air Resistance Force

This is a special type of frictional force that acts upon objects as they travel through the air.

There is a force in the air that slows the movement of a toy airplane.

Applied Force

The force applied to an object by a person or another object is applied force.

A courier is applying a pushing force onto a crate.

Spring Force

A spring force is a force that is exerted by a compressed or stretched spring upon any object that is attached to it.

Elastic metal spring. Eps10 vector illustration contains transparency and blending effects.

Types of forces that involves Action-at-a-distance

Gravitational Force

This is the force with which the earth, moon or other massive object attracts another object towards itself.

On earth all objects experience the force of gravity. This force is downwards.

Gravitational force is the force that allows the ball to come back down.

Force (air resistance) is needed to slow the parachute down for the man to reach the ground safely (gravitational).

Electrical Force

There is a force exerted between any two charged objects. This is electrical force.

There is a negative and a positive charge.Objects with both negative and both positive will repel each other. Objects with one positive and one negative will attract each other.
Examples of electrical forces.

Magnetic Force

This is an attraction or repulsion that arises between electrically charged particles because of their motion.

Both electric and magnetic forces exist among moving electric charges.
Magnetc forces is in magnets.
There is magnetic force in a compass.

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