Year 13 WJEC Physics: Mock Unit Test Analysis & Solutions | Year 13 WJEC 物理：单元测试模拟卷解析

📚 Year 13 WJEC Physics: Mock Unit Test Analysis & Solutions | Year 13 WJEC 物理：单元测试模拟卷解析

Welcome to this detailed walkthrough of a Year 13 WJEC Physics mock unit test. This analysis covers essential A2 topics such as simple harmonic motion, circular motion, capacitors, electric fields, radioactivity, ideal gases, electromagnetic induction, SHM energy, magnetic fields, and gravitation. Work through each worked example to strengthen your problem-solving skills and check your understanding of key equations.

欢迎阅读这份 Year 13 WJEC 物理单元模拟卷的详细解析。本解析涵盖简谐运动、圆周运动、电容器、电场、放射性、理想气体、电磁感应、简谐运动能量、磁场和引力场等 A2 核心主题。通过每一个例题，巩固解题技巧并检验你对关键方程的理解。

1. Simple Harmonic Motion – Maximum Velocity and Acceleration | 简谐运动：最大速度和加速度

A 0.500 kg mass attached to a spring oscillates with an amplitude of 0.080 m and a frequency of 2.00 Hz. Determine the maximum velocity and the maximum acceleration of the mass.

一个 0.500 kg 的物体连接在弹簧上，以振幅 0.080 m、频率 2.00 Hz 振动。求物体的最大速度和最大加速度。

The angular frequency is ω = 2πf = 2π × 2.00 = 4π rad s⁻¹ ≈ 12.57 rad s⁻¹. Maximum velocity is given by vₘₐₓ = ωA.

角频率 ω = 2πf = 4π rad s⁻¹ ≈ 12.57 rad s⁻¹。最大速度由 vₘₐₓ = ωA 给出。

vₘₐₓ = ωA = 4π × 0.080 ≈ 1.01 m s⁻¹

Maximum acceleration uses aₘₐₓ = ω² A. Substitute the values.

最大加速度使用 aₘₐₓ = ω² A，代入数值。

aₘₐₓ = (4π)² × 0.080 ≈ 12.6 m s⁻²

Always keep amplitude in metres and convert frequency to angular frequency correctly to avoid common errors.

务必使用米为振幅单位并将频率正确转换为角频率，以避免常见错误。

2. Circular Motion – Centripetal Force and Banking Angle | 圆周运动：向心力与倾斜角

A car of mass 1200 kg moves around a circular bend of radius 50 m at a constant speed of 15 m/s. Calculate the centripetal force and the ideal angle of banking (assuming no friction).

一辆质量为 1200 kg 的汽车以 15 m/s 的恒定速率通过半径为 50 m 的圆形弯道。请计算向心力及无摩擦时的理想倾斜角。

Centripetal force F꜀ = mv²/r. Substitute the known values.

向心力 F꜀ = mv²/r，代入已知数值。

F꜀ = (1200 × 15²) / 50 = 1200 × 225 / 50 = 5400 N

For banking without friction, tan θ = v² / (rg).

对于无摩擦的倾斜弯道，有 tan θ = v² / (rg)。

更多咨询请联系16621398022（同微信）