Energy Calculator makes physics problems approachable and genuinely interesting. It works through calculations step-by-step, connects formulas to real-world examples, and helps your child understand the underlying concepts — not just memorise equations.
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Kinetic and Potential energy. Here are some of the most popular ways students use Energy Calculator every day:
Energy is the engine that drives all physical processes—from the mechanical motion of falling objects to the chemical reactions in your cells. Yet calculating kinetic and potential energy confuses many GCSE and A-Level Physics students, who struggle to distinguish between the two, apply the correct formula, or recognise when energy converts from one form to another. The Energy Calculator on Applaa demystifies this by guiding you through kinetic energy (energy of motion), gravitational potential energy (stored by height), and elastic potential energy (stored in springs). Rather than memorising formulas, you'll understand what each symbol represents and why the calculation reveals how much energy is stored or released. This tool shows you the powerful principle of energy conservation: total energy stays constant, just changing form. Applaa's free access means every UK student can master energy calculations, from GCSE to A-Level and beyond, building the foundation for understanding everything from roller coasters to planetary orbits.
Start by identifying which type of energy you're calculating: kinetic energy (moving objects), gravitational potential energy (objects at height), or elastic potential energy (stretched springs). For kinetic energy, use KE = ½mv², ensuring mass is in kg and velocity in m/s. For gravitational potential energy, use PE = mgh, where g = 9.8 m/s² and h is the height above the reference point. For elastic PE, use PE = ½kx², where k is the spring constant and x is the stretch. Work through problems, pausing to identify: what type of energy is this? What variables do I have? What am I solving for? Use energy conservation to solve complex problems: total energy at the start equals total energy at the end. Practice converting between energy types to build intuition.
Students often forget that kinetic energy depends on the square of velocity (doubling speed quadruples energy), leading to massive underestimates. Others confuse gravitational PE and kinetic energy, using the wrong formula for the problem type. A frequent error is forgetting to include gravitational field strength (g = 9.8 m/s²) in PE calculations, or using the wrong reference point for zero PE (which can be chosen arbitrarily). Many students fail to apply energy conservation, calculating individual energies without checking that total energy is conserved. The Energy Calculator prevents these errors by making each step explicit and showing how energy conserves throughout a process.
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Calculate kinetic energy for moving objects and gravitational PE for objects at height
Tackle energy conservation problems where energy converts between types, building deep understanding
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Energy is the capacity to do work, measured in Joules. Power is the rate at which energy is transferred, measured in Watts (Joules per second). A light bulb rated at 60 W uses 60 Joules of energy every second. Energy tells you the total work done; power tells you how fast it's done.
This comes from the definition of kinetic energy and how momentum works. When you double velocity, momentum doubles, but the kinetic energy quadruples. This counter-intuitive behaviour is why speeding cars are so much more dangerous—the energy involved rises with the square of speed.
Yes, if you choose a reference point above the object. If you set zero PE at ground level and the object is below ground, PE is negative. But this is just a mathematical convention; what matters is the change in PE, which is independent of your choice of reference point.
Energy conservation gives you a powerful equation: initial total energy = final total energy. If you know some energies at the start and some at the end, you can solve for unknowns. This often avoids complicated force calculations and makes problems much simpler.
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