Work & Power Calculator
Physics work, power & energy calculator
Calculation Mode
Work Calculation
All Work/Power Units
Work Comparison
Power vs Time
Work & Power in Real Life
Compare work and power values in everyday activities and industrial applications
| Activity/Object | Work (Joules) | Power (Watts) | Description |
|---|
Power Output Comparison
Compare power output of various sources and machines
| Source/Machine | Power (Watts) | Power (Horsepower) | Description |
|---|
Interesting Facts
Human Power
Average human can sustain about 75W of power output continuously
Cyclist Power
Professional cyclist can output 400-500W for short periods
Car Engine
Average car engine produces 100-200 horsepower (75-150 kW)
1 Horsepower
1 HP = 746 Watts = 550 ft-lb/s (defined by James Watt)
Understanding Work & Power
What is Work?
Work in physics is defined as the transfer of energy that occurs when a force is applied over a displacement. Work is done when a force causes an object to move in the direction of the force.
- Formula: W = F × d × cos(θ)
- Simple case: W = F × d (when force is parallel to displacement)
- Units: Joules (J), where 1 J = 1 N × 1 m
- Scalar: Work is a scalar quantity (has magnitude but no direction)
What is Power?
Power is the rate at which work is done or energy is transferred over time. It measures how quickly work is performed.
- Formula: P = W/t (Power = Work / Time)
- Alternative: P = F × v (Power = Force × Velocity)
- Units: Watts (W), where 1 W = 1 J/s
- Horsepower: 1 HP = 746 Watts
Work & Power Formulas
Key formulas for work and power calculations:
- Work: W = F × d
- Work (with angle): W = F × d × cos(θ)
- Power: P = W/t
- Power (from force): P = F × v
- Force: F = W/d
- Distance: d = W/F
- Time: t = W/P
Unit Conversions
Common work and power unit conversions:
- 1 Joule (J) = 1 Newton-meter (N·m)
- 1 Joule (J) = 0.239 calories (cal)
- 1 Joule (J) = 0.738 foot-pounds (ft-lb)
- 1 kilojoule (kJ) = 1,000 Joules
- 1 kilowatt-hour (kWh) = 3,600,000 Joules
- 1 Watt (W) = 1 Joule/second
- 1 horsepower (HP) = 746 Watts
Work-Energy Theorem
The work-energy theorem states that the net work done on an object equals the change in its kinetic energy:
- Theorem: W_net = ΔKE = KE_final - KE_initial
- Kinetic Energy: KE = ½mv²
- Positive work: Increases kinetic energy (speeds up object)
- Negative work: Decreases kinetic energy (slows down object)
Power in Everyday Life
- Human at rest: ~80 Watts
- Human walking: ~200-300 Watts
- Human cycling: ~100-400 Watts
- Light bulb: 10-100 Watts
- Car engine: 75,000-150,000 Watts (100-200 HP)
- Power plant: Millions of Watts (MW)
Key Takeaways
Work is Energy Transfer
Work transfers energy when force causes displacement
Power is Rate of Work
Power measures how quickly work is done
Unit Conversions
1 J = 0.239 cal = 0.738 ft-lb
1 Horsepower
1 HP = 746 Watts (defined by James Watt)
Understanding Work and Power in Physics
Work and power are fundamental concepts in physics that describe energy transfer and the rate of energy transfer. Understanding these concepts is essential for analyzing mechanical systems, designing machines, and understanding energy consumption in everyday life.
Work and Power Formulas
Key formulas for work and power calculations:
- Work: W = F × d (Work = Force × Distance)
- Work (with angle): W = F × d × cos(θ)
- Power: P = W/t (Power = Work / Time)
- Power (from force): P = F × v (Power = Force × Velocity)
Unit Conversions
Common work and power unit conversions:
- 1 Joule (J) = 1 Newton-meter (N·m) = 0.239 calories
- 1 kilojoule (kJ) = 1,000 Joules
- 1 kilowatt-hour (kWh) = 3,600,000 Joules
- 1 Watt (W) = 1 Joule/second
- 1 horsepower (HP) = 746 Watts
Work-Energy Theorem
The work-energy theorem states that the net work done on an object equals the change in its kinetic energy:
- Theorem: W_net = ΔKE = KE_final - KE_initial
- Kinetic Energy: KE = ½mv²
- Positive work: Increases kinetic energy (speeds up object)
- Negative work: Decreases kinetic energy (slows down object)
Using This Calculator
Follow these steps:
- Step 1: Select calculation mode (Work, Force, Distance, Power, Time, or Power from Velocity)
- Step 2: Enter the known values with appropriate units
- Step 3: Click "Calculate" to find the unknown value
- Step 4: View results in multiple units (Joules, kJ, calories, kWh)
- Step 5: Check the Compare tab for real-world comparisons
- Step 6: Read the Guide tab to learn about work and power concepts
More Physics Calculators
Explore more physics calculators in our collection, including Force Calculator, Kinetic Energy Calculator, and Acceleration Calculator!