D. Long answer questions,
1. What is light? How does it help us to see an object?
2. What is a shadow? What are the essential things required to form a shadow of an object?
3. Does the size of the shadow of an object depend upon the size of the object? How does the size
of a shadow vary with the distance between a light source and the object?
4. How did people in earlier times use shadows of objects in the sunlight to measure time?
5. Describe an activity to show that light travels in a straight line.
6. What is the difference between an image and a shadow? Does a pinhole camera produce an image
or a shadow of the object?
Answers
Answer:
We are able to see because light from an object can move through space and reach our eyes. Once light reaches our eyes, signals are sent to our brain, and our brain deciphers the information in order to detect the appearance, location and movement of the objects we are sighting at.
2)The following three things are required for a shadow to form: a source of light. an opaque object. a screen or surface behind the object
3)The size of the shadow depends on the size of the object, the distance from the light to the object and the distance from the light to the screen. A bright point of light
4)Using shadows to tell solar time involves keeping track of the position of shadows in relation to a stationary object. Tools like a sundial, shadow stick, or even simply the shadow cast by a tall building can all be used to measure time. ... In Ancient Rome, sundials were a favored method of telling time.
5)Take a rubber tube, stretch it straight and look through it at the flame of the candle with one eye (keeping the other eye closed) [see Figure (a)]. We will find that when the rubber tube is straight, we can see the light of candle flame through it
6)A pinhole camera image is a real image formed at the screen when light from an object is passed through a pin hole. A real image forms at the point where the light rays actually meet. But a shadow is an area with no light formed because of an obstruction to the path of light.
Explanation:
2)a dark shape on a surface that is caused by something being between the light and that surface