NCEA Level 1 Physics (90938) 2013 Assessment Schedule

NCEA Level 1 Physics (90938) 2013 – page 1 of 10

Assessment Schedule – 2013 Physics: Demonstrate understanding of aspects of wave behaviour (90938) Evidence Statement

Q Achievement Achievement with Merit Achievement with Excellence

ONE TWO out of three. (a) A – Red B – Yellow / Green C – Violet

(b) White light is a mixture of colours. One of: • White light contains light of different wavelengths. • White light contains light of different frequencies. • Red has longer wavelength then violet. • Violet has smaller wavelength than red. • Violet has larger frequency than red. • Red has smaller frequency than violet. • Red and violet travel at different speeds in a prism. • Violet is slower than red in a prism. • Red is faster than blue in a prism.

(c) 43° OR 90 – 47 43° 43° OR AND AND Green ray is (mostly) refracted / Green ray is (mostly) refracted / Green ray is (mostly) refracted / emerges from AB. emerges from AB. emerges from AB. AND Green ray is refracted / emerges because the angle of incidence is less than the critical angle. NCEA Level 1 Physics (90938) 2013 – page 2 of 10

(d) One similarity: One similarity: One similarity explained: • Both are a part of the • Both are a part of the Both orange and blue light travel (electromagnetic) spectrum. (electromagnetic) spectrum. at the same speed (in vacuum) • Both are components of white light. • Both are components of white because they are electromagnetic waves. • Both orange and blue light are light. electromagnetic waves. • Both orange and blue light are OR • Travel at same speed in a vacuum. electromagnetic waves. One difference explained: OR • Travel at same speed in a They are different colours because vacuum. they have different frequency / One difference: AND wavelength. • different frequency One difference: • different wavelength • different frequency Orange and blue light refract by • different energy different amounts when they • different wavelength • different speeds in a prism enter / leave less dense / rarer / • different energy • blue refracted more than orange in a more dense mediums because they prism. • different speeds in a prism have different frequency / • blue refracted more than orange wavelength. in a prism (Blue refracts more than orange.)

Orange and blue light travel at different speeds inside the prism/ any medium apart from a vacuum because they have different frequency / wavelength. (Orange travels faster than blue.)

Orange and blue light carry different amounts of energy because they have different frequency / wavelength. (Blue carries more energy than orange.)

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TWO Period is the time for one wave to Period is the time for one wave to (a) pass a point pass a point OR AND 5 5 T = = 0.5 s T = = 0.5 s 10 (units not required) 10 (units not required)

(b) Correctly calculates v: Correctly calculates one of v or f v = f l 4.8 AND correct method for other v v = = 0.40 (m s–1) calculation. so l = 1.2 f OR OR 4.8 Correctly calculates λ with no or v = = 0.40 m s-1 12 Correctly calculates f: incorrect unit. 9 9 f = = 0.60 Hz f = = 0.60 (Hz) 15 15 0.40 l = = 0.667 m 0.60 = 0.7 m or 0.6 recurring

(c) States that waves diffract / bend Explains that the wave fronts / around the wall. crests curve at the edge of the wall OR and travel with the same speed / have the same wavelength. Diagram showing diffraction of waves at the edge of the barrier but OR wavelength not kept the A correct diagram showing same/bending not occurring at correct diffraction of waves at the edge of position. the barrier with no change in wavelength.

(Appendix A) (Appendix A)

(d) States less diffraction / bends around The waves will have a shorter Waves at higher frequency will the wall less(as much as they pass the wavelength / the wave crests are have shorter wavelength (if the edge). closer together, because the speed is the same) OR frequency is higher (and speed the AND same). Shorter wavelength / waves closer When the wavelength is shorter together. OR the amount of diffraction is less, so The waves will diffract less these waves will not diffract as because the wavelength is less (as much as they pass the edge. (Must much as they pass the edge). discuss of “edge” not “gap”)

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THREE States ONE difference. States TWO differences. (a) • Radio waves are transverse waves • Radio waves are transverse while sound waves are waves while sound waves are longitudinal. longitudinal. • Sound waves require a medium • Sound waves require a medium while radio waves do not require while radio waves do not require a medium. a medium. • Radio waves travel faster than the • Radio waves travel faster than sound waves. the sound waves. • Radio waves are electromagnetic • Radio waves are electromagnetic waves and sound waves are waves and sound waves are mechanical waves. mechanical waves. • We can’t hear radio waves but we • We can’t hear radio waves but can hear sound waves we can hear sound waves. (Difference may be implied, eg: (Difference must be implicit, eg Radio waves are electromagnetic Radio waves are electromagnetic waves and sound waves are no.t) waves and sound waves are mechanical waves.)

(b) Correct working for: v = f λ = 800  0.41(= 328 m s–1) OR v = f λ = 800  41/100 (= 328 m s–1) OR Calculates 32800 cm s–1 and shows working which converts to m s–1 (= 328 m s–1)

(c) Calculates the time for sound wave: Calculates the time for sound Calculates the time for sound d 180 wave: wave: t 0.5487 s = = = d 180 d 180 v 328 t = = = 0.5487 s t = = = 0.5487 s (or 0.55 s) v 328 v 328

(or 0.55 s) (or 0.55 s)

(units not required) (If then multiplies by 2 - without (units not required) (units required) stating any assumptions- does not AND AND negate the award of A) (Incorrectly) states that they have States one of: Echo / “There and back” cannot be assumed the speed of the radio • The actual time is slightly more accepted. wave is the same as the speed of than the calculated value. sound. • Radio waves arrive immediately AND etc. Calculates time of 1.1 s. • Time for radio wave to travel 180 m is insignificant/can be ignored. • States that the time is 0.5487 s plus the time for the radio waves to travel to the boat. • Calculates time that radio wave takes to travel using speed of light and adds this. NCEA Level 1 Physics (90938) 2013 – page 5 of 10

(d) The air particles vibrate The air particles vibrate. The air particles vibrate parallel to OR AND wave movement Longitudinal wave. Air particles hit/pass energy to the AND adjacent particles causing them to Air particles pass hit/pass energy vibrate/Create compressions and to the adjacent particles causing rarefactions in air. them to vibrate/Create compressions and rarefactions in air.

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FOUR TWO of three: THREE of three: (a) • Wavelength correctly shown • Wavelength correctly shown • Amplitude correctly shown. • Amplitude correctly shown.

• Motion correctly described as one • Motion correctly described as of: one of: - Up and down - Up and down - Perpendicular - Perpendicular - At right angles to wave - At right angles to wave (movement) (movement) - Transverse - Transverse

(Appendix B) (Appendix B) (Appendix B) Image is located correctly Image is located correctly Image is located correctly OR AND AND ONE ray is drawn correctly with: ONE ray is drawn correctly with: TWO rays are drawn correctly • at least ONE correct arrow • both arrows correct with: • a virtual ray (arrows on virtual rays • virtual ray (arrows on virtual • both arrows correct are neutral, dotted lines for virtual rays are neutral, dotted lines for • virtual ray (without arrows AND rays are neutral) virtual rays are neutral) with dotted lines) • Image location as point of origin • image location as point of origin • image location as point of origin for virtual ray for virtual ray for virtual ray • Reflected ray going into eye. • reflected ray going into eye • reflected ray going into eye.

(Whether image is labelled or OR (Whether image is labelled or not/image is drawn well or not has TWO rays are drawn correctly not/image is drawn well or not has been ignored.) with BOTH arrows correct and been ignored.) includes virtual rays (without arrows) with image location as point of origin for virtual ray. BUT image is incorrectly located. (Whether image is labelled or not/image is drawn well or not has been ignored.) NCEA Level 1 Physics (90938) 2013 – page 7 of 10

(c) Conclusion that he cannot see his Conclusion that he cannot see his Conclusion that he cannot see his feet. feet. feet. AND AND AND ONE of: ONE of: ONE of: • Attempts to draw ray to show / • Ray drawn to show / explains • Ray drawn to show / explains attempts to explain that he cannot that he cannot see his feet that he cannot see his feet see his feet because ray from feet because ray from feet misses his because ray from feet misses his misses his eyes. eyes. head. • Attempts to draw ray to show / attempts to explain that he can only see just below his knee because this is the lowest point that a ray of light can come from, hit

the bottom of the glass, and be (Appendix C) reflected into his eye. (Appendix C) BUT no arrows/reflection not at With arrows and reflection close • Attempts to draw ray to show / to bottom of glass / explanation attempts to explain where the glass bottom of glass (wrong arrows neutral) that angle of incidence = angle of would need to be in order for him relection to see his feet • Ray drawn to show/explains that he can only see just below his • Ray drawn to show / explains knee because this is the lowest that he can only see just below point that a ray of light can his knee because this is the come from, hit the bottom of the lowest point that a ray of light glass, and be reflected into his can come from, hit the bottom of eye. the glass, and be reflected into his eye.

(Appendix D) (Appendix D) BUT no arrows/reflection not at With arrows and reflection close bottom of glass (wrong arrows to bottom of glass/explanation neutral) that angle of incidence = angle of relection • Ray drawn to show/explains where the glass would need to • Ray drawn to show/explains be in order for him to see his where the glass would need to be feet in order for him to see his feet

(Appendix E) (Appendix E) BUT no arrows / reflection not With arrows and reflection close at approximately 0.875 m to approximately 0.875 m. (wrong arrows neutral) • Statement that (part of) the glass • Statement that (part of) the glass needs to be positioned half way needs to be positioned half way between eyes and feet to see feet between eyes and feet to see which is 0.875 m from ground. feet. • Uses protractor to measure angles and draws diagram to show ray missing eye. NCEA Level 1 Physics (90938) 2013 – page 8 of 10

Correct ray diagram (arrows and Correct ray diagram (arrows and normals not required). normals not required). OR AND Refraction . Refraction . OR AND Light slows down in the glass . Light slows down in the glass. OR Bends towards the normal.

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Judgement Statement

Achievement Achievement Not Achieved Achievement with with Merit Excellence Score range 0 – 9 10 – 18 19 – 25 26 – 32 NCEA Level 1 Physics (90938) 2013 – page 9 of 10

Appendix A:

Appendix B:

Appendix C: NCEA Level 1 Physics (90938) 2013 – page 10 of 10

Appendix D:

Appendix E: