The Physics Question Bank

Course: Combined Science + Separate Physics  |  Tier: Foundation + Higher  |  Equation sheet: given in the exam

The equation

wave speed = frequency × wavelength    v = f λ

Quantity	Symbol	Unit
wave speed	v	metres per second (m/s)
frequency	f	hertz (Hz)
wavelength	λ	metres (m)

Rearranged: f = v ÷ λ  |  λ = v ÷ f  |  kHz = × 10³, MHz = × 10⁶, GHz = × 10⁹; speed of EM waves = 3.0 × 10⁸ m/s

Use FIFA for every answer

• F – Formula: write the equation as it appears on the sheet.
• I – Insert: put in the numbers (convert to standard units first).
• F – Fix: rearrange to make the unknown the subject.
• A – Answer: calculate and always give the unit.

Foundation: aim for Q1–8.   Higher: aim for Q4–10. Most questions need rearranging.

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Questions

Q1 (F) A wave on a slinky has a frequency of 50 Hz and a wavelength of 2 m. Calculate its speed.

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F: v = f λ
I: v = 50 × 2
F: v is already the subject
A: 100 m/s

Q2 (F) Sound travels at 340 m/s in air. A guitar note has a frequency of 170 Hz. Calculate its wavelength.

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F: v = f λ
I: 340 = 170 × λ
F: λ = 340 ÷ 170
A: 2 m

Q3 (F) Water waves at the beach travel at 3 m/s with a wavelength of 1.5 m. Calculate their frequency.

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F: v = f λ
I: 3 = f × 1.5
F: f = 3 ÷ 1.5
A: 2 Hz

Q4 (F) Ripples in a ripple tank travel at 0.2 m/s with a frequency of 8 Hz. Calculate their wavelength in cm.

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F: v = f λ
I: 0.2 = 8 × λ
F: λ = 0.2 ÷ 8 = 0.025 m
A: 2.5 cm

Q5 (F) A bat sends out sound at 40 kHz. Sound travels at 340 m/s in air. Calculate the wavelength in mm.

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Convert first: 40 kHz = 40 000 Hz
F: v = f λ
I: 340 = 40 000 × λ
F: λ = 340 ÷ 40 000 = 0.0085 m
A: 8.5 mm

Q6 (F/H) A radio station broadcasts at 100 MHz. Radio waves travel at 3.0 × 10⁸ m/s. Calculate the wavelength.

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Convert first: 100 MHz = 1.0 × 10⁸ Hz
F: v = f λ
I: 3.0 × 10⁸ = 1.0 × 10⁸ × λ
F: λ = 3.0 × 10⁸ ÷ 1.0 × 10⁸
A: 3.0 m

Q7 (F/H) Ultrasound travels through the body at 1500 m/s. A scanner produces waves with a wavelength of 0.5 mm. Calculate the frequency in MHz.

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Convert first: 0.5 mm = 0.0005 m
F: v = f λ
I: 1500 = f × 0.0005
F: f = 1500 ÷ 0.0005 = 3 000 000 Hz
A: 3 MHz

Q8 (F/H) Green light has a wavelength of 5.0 × 10⁻⁷ m and travels at 3.0 × 10⁸ m/s. Calculate its frequency.

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F: v = f λ
I: 3.0 × 10⁸ = f × 5.0 × 10⁻⁷
F: f = 3.0 × 10⁸ ÷ 5.0 × 10⁻⁷
A: 6.0 × 10¹⁴ Hz

Q9 (H) A wave on a skipping rope has a period of 0.25 s and a wavelength of 1.2 m. Calculate the wave speed.

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Step 1 – frequency
F: T = 1 / f
I: 0.25 = 1 ÷ f
F: f = 1 ÷ 0.25 = 4 Hz
Step 2 – speed
F: v = f λ
I: v = 4 × 1.2
A: 4.8 m/s

Q10 (H) A microwave oven uses microwaves with a frequency of 2.45 GHz. Calculate their wavelength, to 2 significant figures. (speed = 3.0 × 10⁸ m/s)

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Convert first: 2.45 GHz = 2.45 × 10⁹ Hz
F: v = f λ
I: 3.0 × 10⁸ = 2.45 × 10⁹ × λ
F: λ = 3.0 × 10⁸ ÷ 2.45 × 10⁹ = 0.1224 m
A: 0.12 m (2 s.f.)