The major difference between force and power is that force is an action on a body or interaction of two bodies. While power is the amount of energy consumed during an action over the body.
Sometimes people get confused between the terms force and power. This section will provide the necessary factors of differentiation between the two with the help of comparison chart.
Content: Force Vs Power
|Basis for Comparison||Force||Power|
|Definition||Force is an interaction |
between two bodies that maintains or changes
the motion of a body.
|Power is the rate at which a work is done.|
|Given as||F = ma||P = W/ t|
|Nature of Quantity||Vector quantity||Scalar quantity|
|Named after||Isaac Newton||James Watt|
Definition of Force
Force is the outcome of the interaction between two entities either directly or indirectly. Or we can say it is a push or pull action performed on an object. It is basically an action that causes a change in the state of rest or state of motion of a body on which it is applied.
As we have discussed above that the interaction can be direct or indirect. Thus this leads to major classification of force,
- Contact Force: This force needs physical interaction between two objects. For example, frictional force, tensional force.
- Action-at-a-distant Force: These forces allow the interaction of two objects without having physical contact between them. For example, gravitational force, electric force.
Newton is the measuring unit of force and is given by:
Force = Mass * Acceleration
Thus we can say 1 Newton is the force needed to provide a 1 Kg mass, an acceleration of 1m/s/s.
Due to the vector nature of force, both magnitude, as well as direction, are the resultant factors in its determination. Consider the figure given here:
In figure (1), FA and FB both forces are acting in the same direction on an object. Thus the net force on the object will be the sum of both the forces acting on it. While in figure (2), the two forces are acting in the opposite direction on the object. Thus the net force will be the difference between the two forces simultaneously acting on it.
So, if the net force acting on a body is 0 then it will remain stationary. But if it is non-zero, then the body will experience either acceleration or deceleration.
Definition of Power
It is basically defined as the amount of energy consumption when an action is performed. More specifically, we can say the rate of doing any work is known as power. So it can be expressed as
Power = Work done / Time taken
Watt is the measuring unit of power. Thus we can say that 1 watt is the power that does work at the rate of 1 Joule per second.
Consider the example of two labors A and B. Each has given a task to build a wall. So, both are doing the same work separately. But A has taken lesser time than B to do the work.
This clearly shows that A is doing the work with more power than B. Therefore, we can say the power of any person or a machine is the ratio of the work doing and the total time taken. We know that work is said to be done when a certain force is applied. So, we can have another formula for power using
P = W/ T
Work = Force * Displacement
Thus, on substituting
P = Force * Displacement / Time
Also, we know
Displacement / Time = velocity
Power = Force * Velocity
Key differences Between Force and Power
- Force is a vector quantity thus both magnitude and direction are required to have the resultant force on an object. As against power is scalar quantity thus is specified by only its magnitude.
- Force is denoted by F. While P is used to denote power applied on an object or body.
- The measuring unit of force is Newton. However, power is specifically measured in watts.
- Force is given by the cross product of mass and acceleration. As against power is given as the ratio of work done per unit time.
- The measuring unit of force is given by the name of scientist Isaac Newton. While the measuring unit of power is given by the name of scientist James Watt.
So, from this discussion, we can conclude that both force and power are the two important terms of science, but force specifies the interaction between objects while power specifies the rate at which any work is done.