📚 Year 10 AQA Engineering: Quick Reference Formulae & Theorems | AQA 工程：公式定理速查手册
This handy quick reference guide covers the essential formulae and theorems needed for Year 10 AQA Engineering. Use it to check your understanding and master the key calculations for mechanics, electronics, and materials. Keep it by your side during revision.
这本便捷的速查手册涵盖了 Year 10 AQA 工程所需的核心公式和定理。用它来检查你的理解，并掌握力学、电子学和材料学中的关键计算。复习时随身携带，随时查阅。
1. Forces and Motion | 力和运动
Average speed is the total distance travelled divided by the time taken: v = d / t where v is speed (m/s), d is distance (m), and t is time (s).
平均速度等于总行驶距离除以所用时间： v = d / t 其中 v 为速度（米/秒），d 为距离（米），t 为时间（秒）。
Acceleration is the rate of change of velocity: a = (v - u) / t where a is acceleration (m/s²), v is final velocity, u is initial velocity, and t is time.
加速度是速度的变化率： a = (v - u) / t 其中 a 为加速度（米/秒²），v 为末速度，u 为初速度，t 为时间。
Final velocity for constant acceleration can be found with: v = u + a t
匀加速运动的末速度可由下式求得： v = u + a t
Newton's Second Law gives resultant force: F = m a where F is force (N), m is mass (kg), and a is acceleration (m/s²).
牛顿第二定律给出了合力： F = m a 其中 F 为力（牛），m 为质量（千克），a 为加速度（米/秒²）。
Weight is the force of gravity on a mass: W = m g where W is weight (N), m is mass (kg), and g is gravitational field strength (≈ 9.8 N/kg on Earth).
重量是重力作用于质量上的力： W = m g 其中 W 为重量（牛），m 为质量（千克），g 为重力场强度（地球上约为 9.8 牛/千克）。
Stopping distance is the sum of thinking distance and braking distance. No single formula, but it highlights the importance of speed and reaction time.
停车距离是反应距离与制动距离之和。虽无单一公式，但它强调了速度与反应时间的重要性。
2. Moments, Torque and Equilibrium | 力矩、扭矩与平衡
Moment of a force about a pivot is the product of the force and the perpendicular distance: M = F × d where M is moment (Nm), F is force (N), and d is perpendicular distance from pivot (m).
力矩是作用力与垂直距离的乘积： M = F × d 其中 M 为力矩（牛·米），F 为力（牛），d 为支点到力作用线的垂直距离（米）。
Principle of moments: For an object in equilibrium, the sum of clockwise moments equals the sum of anticlockwise moments about any pivot.
力矩原理：当物体处于平衡状态时，对任意支点，顺时针力矩之和等于逆时针力矩之和。
Torque is the rotational equivalent of force and is often calculated similarly: T = F × r where T is torque (Nm), F is force, and r is the radius or lever arm.
扭矩是力的旋转等效量，计算方式相近： T = F × r 其中 T 为扭矩（牛·米），F 为力，r 为力臂（半径）。
3. Work, Energy and Power | 功、能和功率
Work done when a force moves an object: W = F × d (force parallel to distance) where W is work (J), F is force (N), and d is distance (m).
做功指力使物体移动： W = F × d （力与距离平行），其中 W 为功（焦），F 为力（牛），d 为距离（米）。
Gravitational potential energy gained or lost:
