Constant Acceleration Formulae 1 | 恒定加速度公式 1

📚 Constant Acceleration Formulae 1 | 恒定加速度公式 1

In Edexcel A-Level Mechanics, constant acceleration formulae are the core tools for describing motion in a straight line when acceleration does not change. They are often called the SUVAT equations because they link displacement, initial velocity, final velocity, acceleration and time.

在 Edexcel A-Level 力学中，恒定加速度公式是描述加速度不变时直线运动的核心工具。它们通常被称为 SUVAT 方程，因为它们把位移、初速度、末速度、加速度和时间联系起来。

This topic is essential for modelling cars, falling objects, projectiles and any motion where acceleration can be treated as uniform over a short interval.

这个主题对于建立汽车、落体、抛体以及任何加速度在短时间内可视为均匀的运动模型都至关重要。

1. What Is Constant Acceleration? | 什么是恒定加速度？

Constant acceleration means that the rate of change of velocity is fixed throughout the motion. In other words, the velocity changes by exactly the same amount in every equal time interval.

恒定加速度意味着速度的变化率在整个运动过程中保持不变。换句话说，在每个相等的时间间隔内，速度的变化量完全相同。

For example, if a car accelerates at 2 m s⁻² in a straight line, its velocity increases by 2 m s⁻¹ every second. This does not mean the velocity is constant; it means the acceleration is constant, so velocity changes linearly with time.

例如，如果一辆汽车沿直线以 2 m s⁻² 加速，它的速度每秒增加 2 m s⁻¹。这并不意味着速度恒定；它表示加速度恒定，因此速度随时间线性变化。

In A-Level mechanics, we usually restrict constant acceleration problems to motion in a straight line. This allows us to use positive and negative signs to show direction.

在 A-Level 力学中，我们通常将恒定加速度问题限制在直线运动。这样我们可以使用正负号来表示方向。

2. The Five SUVAT Variables | 五个 SUVAT 变量

The five variables are best remembered by the acronym SUVAT: s = displacement, u = initial velocity, v = final velocity, a = acceleration, and t = time.

这五个变量最好用缩写 SUVAT 来记忆：s = 位移，u = 初速度，v = 末速度，a = 加速度，t = 时间。

Each SUVAT equation uses exactly four of these five variables. You must be able to identify which variable is not involved in a particular equation.

每个 SUVAT 方程恰好使用这五个变量中的四个。你必须能够识别某个特定方程中未涉及哪个变量。