In physics, a force is any influence that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction. It is measured with the SI unit of newtons and represented by the symbol F. In other words, a force is that which can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity.

Definitions for Force:

1) Force is a push or pull

2) Force is the capacity to do work or cause physical change

3) Force= Mass times acceleration (F = ma)

4) A force is that which changes or tends to change the state of rest or motion of a body.

Examples:

For simplicity sake, all forces (interactions) between objects can be placed into two broad categories: contact forces, and forces resulting from action-at-a-distance.

Contact Forces include: frictional forces, buoyant forces, normal forces, and air resistance forces

Action-at-a-distance forces include: gravitation, electrostatic and magnetic forces.

Measuring Force:

Force is measured using either the English System of Measurements or the International System of Units (SI).

Common Units of Force

—>>SI: Newton (N) 1 N = 0.225 lb;

One Newton (N) of force is defined as the amount of force needed to accelerate 1 kilogram (kg) of mass at a rate of 1 meter per second squared (m/s2).

1 Newton = 1 kg m/sec2 (A kilogram is the amount of weight at which 1 N of force will accelerate at a rate of 1 m/s2.)

—>>English System: Pound (LB) 1 LB = 4.448 N

In English system of measurements, a slug is the amount of mass that 1 pound of force will accelerate at 1 ft/s2, and a pound mass is the amount of mass that 1 LB of force will accelerate at 32 feet/s2.

Describing a Force:

A force is a vector quantity. A vector quantity is a quantity which has both magnitude and direction. To fully describe the force acting upon an object, you must describe both its magnitude and direction. Thus, 10 Newtons of force is not a complete description of the force acting on an object. 10 Newtons, downwards is a complete description of the force acting upon an object.

(Note: What is the difference between vector and scalar quantities? A vector has both strength and direction, a scalar quantity can be described using only 1 quantity, magnitude. Examples of scalar quantities are: time, energy and volume since they only represent magnitude and no direction.

It is a push or pull which changes or try to change the position of rest or of uniform motion of the object.
SI unit of force is newton ( N )
Cgs unit of force is dyne
1 N = 10 5 Dyne
Effect of force
It can change the position of rest.
It can change the position of motion
It can change the shape of the object

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## Answers

In physics, a force is any influence that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction. It is measured with the SI unit of newtons and represented by the symbol F. In other words, a force is that which can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity.

Definitions for Force:

1) Force is a push or pull

2) Force is the capacity to do work or cause physical change

3) Force= Mass times acceleration (F = ma)

4) A force is that which changes or tends to change the state of rest or motion of a body.

Examples:

For simplicity sake, all forces (interactions) between objects can be placed into two broad categories: contact forces, and forces resulting from action-at-a-distance.

Contact Forces include: frictional forces, buoyant forces, normal forces, and air resistance forces

Action-at-a-distance forces include: gravitation, electrostatic and magnetic forces.

Measuring Force:

Force is measured using either the English System of Measurements or the International System of Units (SI).

Common Units of Force

—>>SI: Newton (N) 1 N = 0.225 lb;

One Newton (N) of force is defined as the amount of force needed to accelerate 1 kilogram (kg) of mass at a rate of 1 meter per second squared (m/s2).

1 Newton = 1 kg m/sec2 (A kilogram is the amount of weight at which 1 N of force will accelerate at a rate of 1 m/s2.)

—>>English System: Pound (LB) 1 LB = 4.448 N

In English system of measurements, a slug is the amount of mass that 1 pound of force will accelerate at 1 ft/s2, and a pound mass is the amount of mass that 1 LB of force will accelerate at 32 feet/s2.

Describing a Force:

A force is a vector quantity. A vector quantity is a quantity which has both magnitude and direction. To fully describe the force acting upon an object, you must describe both its magnitude and direction. Thus, 10 Newtons of force is not a complete description of the force acting on an object. 10 Newtons, downwards is a complete description of the force acting upon an object.

(Note: What is the difference between vector and scalar quantities? A vector has both strength and direction, a scalar quantity can be described using only 1 quantity, magnitude. Examples of scalar quantities are: time, energy and volume since they only represent magnitude and no direction.

rate of change of momentum with respect to time

force is pull or push

It is a push or pull which changes or try to change the position of rest or of uniform motion of the object.

SI unit of force is newton ( N )

Cgs unit of force is dyne

1 N = 10 5 Dyne

Effect of force

It can change the position of rest.

It can change the position of motion

It can change the shape of the object