Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Angular Motion - Power and Torque

Angular velocity and acceleration vs. power and torque.

Sponsored Links
  • Work is the result of a force acting over some distance. Work is quantified in joules (Nm) or foot-pounds.
  • Torque is a rotating force produced by a motor’s crankshaft. The more torque the motor produces, the greater is its ability to perform work. Since torque is a vector acting in a direction it is commonly quantified by the units Nm or pound-feet.
  • Power is how rapidly work is accomplished - work in a given amount of time. Power is quantified in watts (J/s) or horse power. 

Power and Torque of Body in Angular Motion

The power of a rotating body can be expressed as

P = T ω        

   = T 2 π nrps  

   = T π nrpm / 30                 (1)

where

P = power (W)

T = torque or moment (Nm)

ω = angular velocity (rad/s)

π = 3.14...

nrps = rotations per second (rps, 1/s)

nrpm = rotations per minute (rpm, 1/min)

  • rad = 360o / 2 π =~ 57.29578..o

Note! - an object - like an electric motor - can have an active moment without rotation, but without rotation (ω = 0) there is no power produced.    

In imperial units

P = T nrpm / 5252                   (1b)

where

P = power (hp)

T = torque (ft lbf

Example - Torque created by Rotating Motor

An electric motor runs with 3600 rpm with an measured power consumption of 2000 W. The torque created by the motor (without losses) can be calculated by rearranging (1) to

T = 30 P / (π nrpm

   = 30 (2000 W) / (π (3600 rpm))  

   = 5.3 Nm

Torque Calculator

Motor - Torque vs. Power and rpm

Download and print Motor - Torque vs. Power and rpm chart

Torque of a Body in Angular Motion

T = I α                    (2)

where

I = moment of inertia (kg m2, lbf ft s2)

α = angular acceleration (rad/s2)

Sponsored Links

Related Topics

  • Dynamics

    Motion - velocity and acceleration, forces and torque.

Related Documents

Sponsored Links

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

Citation

This page can be cited as

  • The Engineering ToolBox (2008). Angular Motion - Power and Torque. [online] Available at: https://www.engineeringtoolbox.com/angular-velocity-acceleration-power-torque-d_1397.html [Accessed Day Month Year].

Modify the access date according your visit.

close

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































9.27.11

Sponsored Links
.