Directions: Use the information provided and your knowledge of Physical Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Physical Science to answer the following questions. Show all work where necessary.
Source: https://www.clovermeadowsbeef.com/how-do-cows-stay-warm-in-winter/
On a cold winter day, students observe cows calmly chewing hay in a snowy field. Even though the air is freezing, the cows stay warm, move around, and grow throughout the season. The hay they eat was once green grass grown in the summer sun.
Students ask: How does eating dried plants give cows enough energy to stay warm in winter?
This investigation helps students understand that energy stored in plants originally came from the Sun, and animals use that stored energy for warmth, motion, growth, and body repair.
Animals need energy to keep warm, move, grow, and repair their bodies. Cows get this energy from food, just like all animals do. During the summer, grass grows using sunlight to make chemical energy through photosynthesis. Farmers cut and dry this grass to make hay, which cows eat in the winter.
Even though hay looks dry and brown, it still contains the stored solar energy that the grass collected when it was alive. When cows eat hay, their bodies break it down and release that stored energy. Cows use some of this energy to keep their large bodies warm in cold weather. They also use energy to walk around, chew, digest food, and grow.
Scientists can measure how much energy cows get from hay and how much they use to maintain body warmth and movement. These measurements show that the energy cows use in winter originally came from the Sun during summer.
Hay Eaten (kg) | Energy in Hay (kJ) |
|---|---|
2 | 9000 |
3 | 13500 |
4 | 18000 |
Activity | Energy Used (kJ) |
|---|---|
Body Warmth | 10000 |
Movement | 4000 |
Growth/Repair | 2000 |
Where did the energy stored in the hay originally come from?
Look at Table 1. How does the energy in hay (kJ) change as the amount of hay eaten increases?
Using Figure 1, describe the pattern between hay eaten (kg) and energy stored (kJ).
Look at Table 2 and Figure 2. How does the cow use energy across different body functions during winter?
Which activity uses the most energy in the cow?
How does the cow–hay investigation show that the energy animals use originally came from the Sun?
Respond using Claim, Evidence, and Reasoning.