194 Our Surroundings 



3. What is meant by an opaque object? A transparent object? A 

 translucent object? 



4. Describe an experiment to show the nature and cause of shadows. 



5. Has the color of a house any effect on the depth of shadow it casts? 



6. What is a mirror? State the effects of curved mirrors on the appear- 

 ance of images. 



7. What is meant by refraction of light? Give an example. 



8. Describe the spectrum and state its cause. 



9. What causes a rainbow? 



10. State the difference between a convex lens and a concave lens. 



11. Sometimes objects seen through a window appear distorted. Why? 



12. Why is smoked glass used in observing an eclipse of the sun? 



13. Is it true or false that a straight stick appears bent if thrust into 

 water ? 



14. Is it true or false that indirect lighting causes less shadows? 



15. Make a labeled drawing of the apparatus used to show that light 

 travels in straight lines. 



16. How is artificial light produced? 



17. What precautions should you observe in the use and care of the eyes? 



18. Over which shoulder should light come for a left-handed writer? 

 Explain. 



19. Why does an object cast a shadow in the sunlight? 



20. Why does the shadow of an object vary in length at different times 

 during the day? 



PROJECTS 



1. Compare different methods of lighting, as to advantages, disadvantages 

 and costs. 



2. Study and report on sunlight in the home as affected by windows, 

 shades, wall paper, and draperies. 



3. Study a camera, (a) Make diagrams of the camera and of the human 

 eye. (b) Label the part of the eye that corresponds to each of the 

 following parts of the camera: (1) lens, (2) diaphragm, (3) film 

 (plate or screen), (c) Compare the focusing structure of the eye 

 with that of the camera. 



OUTDOOR OBSERVATION 



1. On your walks to and from school observe and record how different 

 kinds of objects and materials absorb or reflect light. 



2. Observe shadows cast by different objects, and record your findings. 



REFERENCES 



Lectures on Light Tyndall 



Principles of Light and Color Babbitt 



