Physics Energy Calculator — KE, PE, Work Done
Calculate kinetic energy (KE = ½mv²), potential energy (PE = mgh), and work done (W = Fd). Enter mass, velocity, height, or force to get instant results with unit explanations.
KE = ½mv²
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Kinetic Energy
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Kilojoules (kJ)
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Calories (cal)
Step-by-Step Solution
Energy Formulas
- Kinetic Energy: KE = ½ × mass × velocity² (Joules)
- Potential Energy: PE = mass × g × height (Joules)
- Work Done: W = Force × distance (Joules)
- Energy conversion: 1 kJ = 1000 J, 1 cal = 4.184 J
Frequently Asked Questions
What is kinetic energy?
Kinetic energy (KE) is the energy an object possesses due to its motion. It is calculated as KE = ½mv², where m is mass in kilograms and v is velocity in metres per second. The result is in Joules (J).
What is potential energy?
Gravitational potential energy (PE) is the energy stored in an object due to its height above a reference point. PE = mgh, where m is mass (kg), g is gravitational acceleration (9.81 m/s²), and h is height (m). The result is in Joules.
What is work done?
Work (W) is done when a force moves an object through a distance. W = F×d, where F is force in Newtons and d is distance in metres. Work is measured in Joules. Work equals the energy transferred to or from an object.
What is the unit of energy?
The SI unit of energy is the Joule (J). 1 Joule = 1 kg·m²/s². Other common units include kilojoules (kJ = 1000 J), calories (1 cal ≈ 4.184 J), and kilowatt-hours (1 kWh = 3,600,000 J).
What is the relationship between KE and PE?
According to the conservation of energy, the total mechanical energy (KE + PE) in a closed system remains constant. When an object falls, PE converts to KE. At the top, all energy is PE; at the bottom, all is KE (ignoring friction).