Exam

Gizmo Student Exploration week 6 Lab: Penumbra Effect Gizmo [ALL ANSWERED]

Gizmo Student Exploration week 6 Lab: Penumbra Effect Gizmo [ALL ANSWERED] Vocabulary: eclipse, penumbra, point source, umbra Prior Knowledge Questio ns (Do these BEFORE using the Gizmo.) Try this experiment: Shine a flashlight (or a desk lamp) on your hand so that it casts a shadow on a sheet of white paper. Hold your hand about 15–30 cm (6–12 inches) above the paper. 1. Look at the edges of the shadow. Are they sharp or fuzzy? They are fuzzy 2. Move your hand up and down. How does this affect the fuzziness of the shadow? The closer it gets the more fuzzy 3. Why do you think the shadow has fuzzy edges? The light sources are obstructed and by objects and appear fuzzy Gizmo Warm-up The fuzzy edge of a shadow is the penumbra, a region where light is only partially blocked. The Penumbra Effect Gizmo™ demonstrates why penumbras form. To begin, check that the Number of lights is 1. Click the light to turn it on. The gray block casts a shadow. 1. The light is a point source, which means that all of the light rays emanate from a single point. Does the resulting shadow have sharp or fuzzy edges? It has a clear defined shadow 2. Increase the Number of lights to 2. How does this affect the shadow? It starts to become fuzzy 3. The central, dark part of the shadow is the umbra. Would you be able to see either of the lights if you were standing in the umbra? Explain. You would not be able to see the light if you were standing directly behind because the object making a shadow would block it out .