4 11969.02 Question 1 • Extension (disposable) spring unextended length 20 mm • 100 g mass holder × 2 • 100 g slotted mass × 4 • Half metre rule • Retort stand, boss head and clamp • Labels Question 2 • 22 Ω resistor × 4 • 15 Ω resistor × 2 • Milliammeter (range 0–200 mA reading to 0.1 mA) • Voltmeter (range 0–20V to 0.01V) • Connecting wires with fitted plug × 5 • Crocodile clips × 2 • 4.5 V d.c. supply (batteries or power pack) • Box or similar to conceal power supply • Masking tape • Labels Question 3 • Single layer DVD or CD ROM × 4 • 10 g mass (diameter approx. 33 mm) × 2 • 20 g mass (diameter approx. 33 mm) × 2 • Stopclock • Double sided foam sticky pads, e.g. Sellotape sticky fixers × 6 • Labels/marker suitable for writing on DVD