4. Which of the following is not needed to make a model of the water cycle?
an energy source
water
a closed container
a drain
5. Which of the following explains why water is a limited resource?
Water is present on Earth in a fixed amount that does not change.
Water is degrading slowly with time.
Only water not present in oceans is available for living things to use.
Once it ends up as groundwater, water is no longer available for living things to use.
4. D
D
your welcome
To determine the correct answer for question 4 regarding what is not needed to make a model of the water cycle, let's go through each option:
1. An energy source: In the water cycle, energy from the sun is necessary for evaporation and transpiration, so an energy source is needed to replicate these processes in a model. Therefore, this option is not the correct answer.
2. Water: The water cycle involves the continuous movement of water through various stages, from evaporation to condensation to precipitation and so on. It is crucial to have water present in the model to simulate these processes accurately. Therefore, this option is not the correct answer.
3. A closed container: The water cycle occurs naturally and is an open system. Water evaporates, condenses, and precipitates, going through various stages of the cycle. A closed container would hinder this natural movement of water in the model. Therefore, this option is the correct answer.
4. A drain: In a model of the water cycle, it is essential to replicate the continuous movement of water without any loss. A drain would lead to the loss of water, which does not accurately represent the water cycle. Therefore, this option is not the correct answer.
Based on this analysis, the correct answer for question 4 is "a closed container."
Now, let's move on to question 5 and analyze the provided options:
1. Water is present on Earth in a fixed amount that does not change: This option correctly states that the total amount of water on Earth remains constant. The water may change states or be distributed differently, but the overall quantity remains the same. Therefore, this option is not the correct answer.
2. Water is degrading slowly with time: This option is not accurate. Water does not degrade or deteriorate over time. It can become polluted or contaminated but does not degrade in the sense of diminishing its quantity. Therefore, this option is not the correct answer.
3. Only water not present in oceans is available for living things to use: This option correctly acknowledges that a significant portion of water, around 97.5%, is found in oceans and is saline. Only a small fraction of freshwater is available for living things to use. Therefore, this option is the correct answer.
4. Once it ends up as groundwater, water is no longer available for living things to use: This option is not entirely accurate. Although groundwater is not as easily accessible as surface water, it can be extracted and used for various purposes. Therefore, this option is not the correct answer.
Based on this analysis, the correct answer for question 5 is "Only water not present in oceans is available for living things to use."