Reflection
Muhtasari
Look at the front of an ambulance in your mirror and the word across its bonnet suddenly makes sense. It was painted back to front on purpose, because the only driver who needs to read it is the one looking at it through a piece of silvered glass. Somebody in a paint shop had to know, in advance and exactly, what a mirror does to a shape. They were not guessing. Reflection is one of the most precisely predictable things in the whole of physics, and the rule behind it fits into nine words.
This lesson turns that rule into a skill. You will learn where the normal is drawn and why every angle in this topic is measured from it rather than from the shiny surface itself, which is where most of the marks on this topic are quietly thrown away. You will then learn to build a ray diagram: to place the image behind the mirror by construction, find the exact point where the light bounces on its way to somebody's eye, and follow how that path shifts when the object moves, when the eye moves, or when the mirror itself is turned. Along the way you will see the same rule at work on a sound wave returning from a wall, because your specification states it for waves in general and not for light alone. By the end you will be able to say why the letters on the ambulance are reversed left to right and not top to bottom, which is a question far more people get wrong than get right. All three statements in this topic are examined on both the Core Tier and the Extension Tier.
Malengo
- When waves are reflected the angle of incidence is equal to the angle of reflection.
- The normal is a construction line perpendicular to the reflecting surface at the point of incidence.
- The image produced in a plane mirror is virtual, upright and laterally inverted. Students will be expected to be able to construct ray diagrams to represent the changing path of reflected rays.
Ramani ya mawazo
Mada hii imechorwa ili uone jinsi mawazo yanavyounganika.
Fungua ramani ya mawazo kwenye programu
Maelezo ya Somo
Dokezo Kamili la Somo Linapatikana kwenye Programu ya Green Bridge
Pata programu ya Green Bridge CBT kwenye simu au kompyuta yako kwa maktaba kamili ya IGCSE: mitihani ya miaka iliyopita, miongozo ya usahihishaji, ramani za mawazo, kadi za marudio na masomo ya sauti.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Reflection. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- A ray of light strikes a plane mirror. The angle between the incident ray and the surface of the mirror is 30 degrees. What is the angle of reflection? A. 15 degrees B. 30 degrees C. 60 degrees D. 120 degrees Answer: C
- What is the normal in a reflection diagram? A. A ray of light travelling along the reflecting surface B. A construction line drawn perpendicular to the reflecting surface at the point of incidence C. The reflected ray D. A line drawn parallel to the mirror through the object Answer: B
- Which set of words correctly describes the image formed in a plane mirror? A. Real, upright and laterally inverted B. Virtual, upside down and laterally inverted C. Virtual, upright and laterally inverted D. Real, upside down and the same size Answer: C
- An object stands 12 cm in front of a plane mirror. How far is the image from the object? A. 6 cm B. 12 cm C. 24 cm D. 144 cm Answer: C
- A plane mirror is rotated through 15 degrees while the incident ray is kept fixed. Through what angle does the reflected ray turn? A. 7.5 degrees B. 15 degrees C. 30 degrees D. 45 degrees Answer: C
Fanyia kazi maswali haya kwenye programu
Fanyia kazi maswali haya kwenye programu
Vitabu Vinavyopendekezwa
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Reflection? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
Pakua Programu Kwenye Google Playstore
Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.
