Physics Essentials Calculator

The unit system toggle currently converts mass, acceleration, and force between metric and imperial specifically within Force mode, since that's where pound-mass and pound-force conversions are wired into the calculation. The other modes — kinematics, energy, momentum, power, and projectile motion — compute and display their results in SI units regardless of the toggle's position, so switching modes resets you to metric inputs and outputs.

These represent the two idealized extremes of how real collisions actually behave: a perfectly inelastic collision has the objects stick together afterward (like a car crash where bumpers lock), while a perfectly elastic collision has both objects bounce apart with total kinetic energy conserved (like idealized billiard balls). Most real-world collisions fall somewhere between these two extremes, which is why physics problems commonly compute both bounds to frame the range of realistic outcomes.

It assumes a flat 0.7g deceleration rate, a reasonable approximation for a hard, controlled stop on dry pavement, but actual braking distance varies substantially with road surface, tire condition, vehicle weight distribution, and whether anti-lock brakes are engaged. Treat this figure as an order-of-magnitude physics illustration of how kinetic energy relates to stopping distance, not a precise real-world braking prediction for a specific vehicle.

No — Distance is collected but every solve option in that mode (final velocity, distance, acceleration, or time) recomputes distance itself from the initial velocity, acceleration, and time you enter, so whatever value you type into Distance is never read by the calculation.

Ignoring air resistance (drag) keeps the equations solvable with simple algebra and trigonometry, which is why it's the standard assumption for introductory kinematics problems, and it stays reasonably accurate for dense, compact, relatively slow-moving objects like a thrown ball over a short distance. It breaks down significantly for lightweight or oddly shaped objects, high launch velocities, or long flight distances — a real baseball, golf ball, or bullet's actual trajectory diverges meaningfully from this idealized parabola once air resistance has enough time and speed to matter.