Study guide: Light, shadows, and material choices
Use light observations to explain a model and choose a material for a purpose.
Ideas to explain in your own words
- Use a supplied observation to choose a material for a purpose.
- Match light observations to transparent, translucent, or opaque.
- Explain a dark area using a blocked light path.
- Check whether one material satisfies two stated requirements.
Watch your reasoning
- The thick card has the recorded result “no light passes through.” That evidence fits the goal of blocking light. The clear sheet and tissue let light through.
- B transmits light while making the image blurry. That is the supplied translucent result; C blocks light and A gives a clear image.
- The without-card observation says the screen is bright. Removing the opaque obstacle allows the previously blocked paths to reach it in the model.
- K lets light through while blurring the view. J preserves a clear view and L blocks the required light.
A worked review example
Choose a Light-blocking Screen: For a window that lets light through, the clear sheet fits the recorded result. The thick card would block the light instead. Name a Material’s Light Property: A is transparent, B is translucent, and C is opaque. A and B both transmit light, but only A gives a clear view in these notes. Trace a Shadow Model: The lamp → card path is blocked. The region behind the card receives less lamp light, so it is darker than the nearby screen in this one-lamp model. Choose for Two Light Goals: K has “yes” for transmitting light and “yes” for blurring the picture. J is yes/no, and L is no/yes. K is the only cover meeting both recorded requirements.
Make a practice plan
- Try the supplied lesson problems without looking at the answers.
- Compare your method with the worked examples and explain any correction.
- Use the new review cases, then complete the transfer task on paper or in your own document.