Science: Pitch & Elastic Bands

FSCE-Style Compass • Paper 3 Section 3 • 6 Questions

6 Graded Questions

Experiment Background

A class stretched elastic bands of different lengths over a box and plucked each one, listening to the pitch (how high or low the sound is). They used the same kind of band, stretched by the same amount each time.

Band length (cm)	10	15	20	25
Pitch heard	Very high	High	Low	Very low

13 The class used the same kind of band and stretched each one by the same amount. Why was this important?

A To make it a fair test, so that length is the only thing changing. B To make the experiment finish more quickly. C So that every band would make the same pitch. D Because longer bands are harder to stretch.

Examiner Note: Keeping the band type and amount of stretch the same makes it a fair test, so any change in pitch is caused by length alone (Answer: A).

14 The class wants a band that sounds between the 15 cm band ('High') and the 20 cm band ('Low'). About how long should the band be?

A About 12 cm B About 17 cm C About 22 cm D About 30 cm

Examiner Note: A pitch between the 15 cm 'High' band and the 20 cm 'Low' band needs a length between 15 cm and 20 cm — about 17 cm (Answer: B).

15 What is the pattern between band length and pitch in the class's results?

A The shorter the band, the higher the pitch B The shorter the band, the lower the pitch C The length makes no difference to the pitch D The longer the band, the higher the pitch

Examiner Note: As length increases (10 -> 25 cm), pitch falls (Very high -> Very low). Therefore, shorter bands produce higher pitch (Answer: A).

16 A new band is 12 cm long. Using the pattern, what pitch is it most likely to make?

A Very low, like the 25 cm band B High - a little lower than the 10 cm band but higher than the 15 cm band C Lower than the 25 cm band D Exactly the same as the 20 cm band

Examiner Note: 12 cm lies between 10 cm ('Very high') and 15 cm ('High'), so its pitch sits right between the two (Answer: B).

17 Using the pattern, what pitch would you expect from a 30 cm band - longer than any the class tested?

A Higher than the 10 cm band B The same as the 25 cm band C Too high for the class to hear D An even lower pitch than the 25 cm band

Examiner Note: Longer bands produce lower pitches; 30 cm is longer than 25 cm ('Very low'), so the sound would be even lower still (Answer: D).

18 On a guitar, pressing a string makes it shorter and this makes the note HIGHER. A pupil claims the class's band results show the OPPOSITE happening with the bands. Is the pupil right?

A Yes - with the bands, a shorter length gave a lower pitch B Yes - length changes the pitch on a guitar but not on the bands C No - the bands behave the same way: a shorter length gave a higher pitch, just like the guitar string D No - but only because elastic bands and guitar strings are made of different materials

Examiner Note: The bands show shorter = higher pitch (10 cm Very high, 25 cm Very low), which is the exact same direction as the guitar. The pupil's claim is incorrect (Answer: C).

Science: Pitch & Elastic Bands

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