💨 速度计算器Velocity Calculator

使用说明与常见问题How-to & FAQ

「速度计算器」是什么？What is the Velocity Calculator tool?

用位移和时间（v = d/t）或初速度、加速度和时间（v = v₀ + at）计算速度，并换算成 km/h、mph。Find velocity from displacement and time (v = d/t) or from initial velocity, acceleration and time (v = v₀ + at), in m/s, km/h and mph.

如何使用「速度计算器」？How do I use the Velocity Calculator tool?

在「速度计算器」中，填写「计算方式」、「位移 d (m)」、「时间 t (s)」、「初速度 v₀ (m/s)」、「加速度 a (m/s²)」等参数，结果会随输入实时计算并显示在下方。In the Velocity Calculator: Fill in "Method", "Displacement d (m)", "Time t (s)", "Initial velocity v₀ (m/s)", "Acceleration a (m/s²)"; results are recalculated instantly as you type.

速度和速率有什么区别？What is the difference between velocity and speed?

速度（velocity）是矢量，有方向，可为负；速率（speed）是速度的大小。本工具按一维运动计算：位移 d、初速度 v₀、加速度 a 可为负，负值表示反方向；时间 t 不能为负（v = d/t 时须大于 0）。v² = v₀² + 2ad 模式给出的是速度大小（速率）。Velocity is a vector with direction (it can be negative); speed is its magnitude. This tool works in one dimension: displacement d, initial velocity v₀ and acceleration a may be negative (opposite direction); time t cannot be negative (and must be > 0 for v = d/t). The v² = v₀² + 2ad mode gives the magnitude (speed).

计算结果可以用于作业或工程吗？Can I use the results for homework or engineering?

「速度计算器」使用教科书标准公式（公式写在说明和常见问题中），适合学习和估算核对；涉及安全的工程设计请以规范和实测为准。The Velocity Calculator uses standard textbook formulas (given in the description and FAQ), which is good for learning and checking estimates; for safety-critical engineering follow codes and measured values.

「速度计算器」免费吗？需要注册吗？Is the Velocity Calculator free? Do I need an account?

「速度计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Velocity Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.