Finding units for power via Dimensional Analysis? Makes no sense

Click For Summary
SUMMARY

The discussion centers on determining the units for power through dimensional analysis, specifically focusing on the relationship between power, work, and time. Power is defined as the rate of work performed, expressed in watts (W), which is equivalent to joules per second (J/s). The analysis reveals that work is calculated as force multiplied by distance, where force is measured in newtons (N) and distance in meters (m), leading to the conclusion that power can be expressed in base units of kilograms (kg), meters (m), and seconds (s).

PREREQUISITES
  • Understanding of dimensional analysis
  • Knowledge of units of measurement: joules, watts, newtons
  • Basic physics concepts: work, force, energy
  • Familiarity with the relationship between power, work, and time
NEXT STEPS
  • Study the derivation of power units in physics
  • Learn about dimensional analysis techniques in detail
  • Explore the relationship between force, mass, and acceleration using Newton's second law
  • Investigate the implications of unit conversions in physical equations
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding the fundamentals of power and its units through dimensional analysis.

Elysian
Messages
33
Reaction score
0

Homework Statement



"Power is the rate at which work is performed.

Power is signified by W for watts.

Power is also the amount of energy transmitted in a unit of time (s).

Energy is measured in joules. Joules have the units of Newton∙meters.

A Newton is a unit of force. It is equal to the amount of force required to give a 1 kilogram mass and acceleration of one meter per second squared."

Using the aforementioned information, determine the units for power by completing a dimensional analysis.


Homework Equations


Down


The Attempt at a Solution



Ok so I know that the units for power are Joules/seconds.. How would you go about getting this by dimensional analysis at all?

So I've done

P = J/s

Power (P) = Work (W)/time (t)
P is in Watts (W)
Watts is J/s

Not sure at all what to do, this is worded so weirdly.. If anyone could help me see what exactly to do, that'd be appreciated.
 
Physics news on Phys.org
Currently, you have done this question by working backwards. You were pretty much there.

The unit for Force is Newtons

Work = force * distance. Hence, the units for work is Newtons * distance (Nm) which is equivalent to Joules.

Now, reapply this to what you've already done and you're pretty much there.
 
It might be asking you to get strictly down to units of kg, m, and s.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
9K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
2
Views
2K
Replies
3
Views
1K
  • · Replies 5 ·
Replies
5
Views
8K
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K