A-Level Physics: Typical Example Questions Explained in Detail | A-Level 物理：典型例题详解

📚 A-Level Physics: Typical Example Questions Explained in Detail | A-Level 物理：典型例题详解

A-level Physics exams require not only understanding of concepts but also the ability to solve problems step by step. This article provides detailed walkthroughs of 12 typical exam-style questions covering mechanics, electricity, waves, quantum physics, and more. Each example includes English and Chinese explanations, highlighting key formulas and common pitfalls.

A-Level物理考试不仅要求理解概念，还要求逐步解决问题的能力。本文详细讲解12道典型考题，涵盖力学、电学、波和量子物理等。每道例题都配有中英文解析，突出重点公式和常见易错点。

1. Projectile Motion | 弹射运动例题解析

A ball is projected from ground level with an initial speed of 20 m/s at an angle of 30° to the horizontal. Taking g = 9.8 m/s², calculate: (a) the maximum height, (b) the total time of flight, and (c) the horizontal range.

一个小球以20 m/s的初速度从地面以与水平方向成30°角斜向上抛出，取g = 9.8 m/s²。计算：(a) 最大高度，(b) 总飞行时间，(c) 水平射程。

We resolve the velocity into horizontal and vertical components. Horizontal: u_h = u cosθ = 20 cos30° = 20 × (√3/2) ≈ 17.32 m/s. Vertical: u_v = u sinθ = 20 sin30° = 10 m/s.

我们将速度分解为水平和竖直分量。水平分量：u_h = u cosθ = 20 cos30° = 20 × (√3/2) ≈ 17.32 m/s。竖直分量：u_v = u sinθ = 20 sin30° = 10 m/s。

At maximum height, the vertical velocity becomes zero. Using v² = u² + 2as in the vertical direction: 0 = (u sinθ)² – 2g H ⇒ H = (u sinθ)² / (2g) = 10² / (2 × 9.8) = 100/19.6 ≈ 5.10 m.

在最高点，竖直分速度为零。对竖直方向使用v² = u² + 2as：0 = (u sinθ)² – 2g H ⇒ H = (u sinθ)²/(2g) = 10²/(2×9.8) = 100/19.6 ≈ 5.10 m。

Time to reach the peak: v = u_v – g t ⇒ 0 = 10 – 9.8 t ⇒ t_up = 10/9.8 ≈ 1.02 s. Total flight time T = 2 t_up ≈ 2.04 s.

上升到最高点的时间：v = u_v – g t ⇒ 0 = 10 – 9.8 t ⇒ t_up = 10/9.8 ≈ 1.02 s。总飞行时间 T = 2 t_up ≈ 2.04 s。

Horizontal range R = u_h × T = 17.32 × 2.04 ≈ 35.3 m. Alternatively, using the formula R = (u² sin2θ)/g = (400 sin60°)/9.8 ≈ 35.35 m.

水平射程 R = u_h × T = 17.32 × 2.04 ≈ 35.3 m。也可用公式 R = (u² sin2θ)/g = (400 sin60°)/9.8 ≈ 35.35 m。

2. Newton’s Laws and Connected Particles | 牛顿定律与连接体例题

Two masses, 5 kg and 3 kg, are connected by a light inextensible string passing over a smooth pulley. The 5 kg mass rests on a smooth horizontal table, while the 3 kg mass hangs freely. Calculate the acceleration of the system and the tension in the string (g = 9.8 m/s²).

两个质量分别为5 kg和3 kg的物体，通过一根轻质且不可伸长的绳子跨过光滑定滑轮相连。5 kg物体放在光滑水平桌

Published by TutorHao | A-Level Physics Revision Series | aleveler.com

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