Question

prior knowledge questions (do these before using the gizmo.)

1. at what time of day is sunlight strongest – in the early morning (when the sun has just risen) or at noon (when the sun reaches its highest point)?
2. at what time of year does the noon sun rise highest in the sky?
3. based on your answers, why is it warmer in summer than in winter?

gizmo warm-up
the reasons for seasons have a lot to do with the angle at which the sun’s rays hit earth. to see why, select the plate tab on the seasons: why do we have them? gizmo. the image shows a solar panel (plate m) facing the sun. check that the axis angle is set to 0°.

1. click fire to release 100 “rays” of sunlight. look next to “number of hits” below the plate.

how many of these rays hit plate m?

1. click reset. change the axis angle to 40°, and click

Answer:

To solve these questions, we analyze each part based on the Gizmo Warm - up activity about the reasons for seasons (related to the angle of the Sun's rays hitting the Earth):

Prior Knowledge Questions

1.

• Explanation for the time of strongest sunlight: Sunlight is strongest at noon. This is because at noon, the Sun is at its highest point in the sky. When the Sun is at a higher position, its rays travel a shorter path through the Earth's atmosphere. As a result, the rays are less scattered and more concentrated on the Earth's surface, making the sunlight stronger compared to the early morning (when the Sun has just risen) when the Sun is low in the sky and its rays have to pass through a thicker layer of the atmosphere, leading to more scattering and less intensity.
• Answer: At noon.

2.

• Explanation for the time of year with the highest noon Sun: The noon Sun rises highest in the sky during the summer (for the hemisphere experiencing summer). This is due to the tilt of the Earth's axis. During summer in a particular hemisphere, that hemisphere is tilted towards the Sun. This tilt causes the Sun's rays to hit the hemisphere more directly (at a steeper angle) at noon, making the Sun appear higher in the sky. In winter, the hemisphere is tilted away from the Sun, and the noon Sun is lower in the sky.
• Answer: During summer (for the relevant hemisphere).

3.

• Explanation for why it is warmer in summer: It is warmer in summer than in winter mainly because of two factors related to the Sun's rays. First, as mentioned earlier, in summer, the Sun is higher in the sky at noon (due to the Earth's axial tilt), so its rays are more direct. More direct rays mean that the same amount of solar energy is concentrated over a smaller area of the Earth's surface, leading to more heating. Second, the days are longer in summer, which means there is more time for the Earth's surface to absorb solar energy. In winter, the Sun is lower in the sky, its rays are more spread out, and the days are shorter, resulting in less heating of the Earth's surface.
• Answer: It is warmer in summer because the Sun's rays are more direct (due to the Earth's tilt) and the days are longer, leading to more solar energy absorption by the Earth's surface.

Gizmo Warm - up

1.

• Explanation for the number of rays hitting Plate M: To find the number of rays hitting Plate M when we release 100 rays with the Axis angle set to \(0^{\circ}\), we would actually perform the action in the Gizmo (click "Fire" to release 100 rays and then check the "Number of hits" next to Plate M). From typical results of this Gizmo activity (when the axis angle is \(0^{\circ}\), representing a situation like the equator or a time when the tilt doesn't affect the plate's orientation towards the Sun in a skewed way), we find that the number of rays hitting Plate M is usually around 100 (or a value close to 100, depending on the exact simulation, but in the basic setup with the plate facing the Sun directly at \(0^{\circ}\) axis angle, most of the 100 rays will hit the plate). Let's assume after performing the action, we see that the number of hits is 100 (this is a typical result for this setup where the plate is directly facing the Sun's rays).
• Answer: 100 (this answer is based on the expected result from the Gizmo simulation when the Axis angle is \(0^{\circ}\) and the plate is facing the Sun).

2.

• Explanation for the effect of changing the Axis angle to \(40^{\circ}\): When we change the Axis angle to \(40^{\circ}\) and click "Fire" again, the number of rays hitting Plate M will decrease. This is because changing the Axis angle (simulating the Earth's axial tilt or a change in the orientation of the plate relative to the Sun's rays) causes the Sun's rays to hit the plate at a more oblique (slanted) angle. When the rays hit at a slanted angle, they are spread out over a larger area of the plate (or some rays miss the plate entirely), so the number of rays that actually hit the plate (the "Number of hits") will be less than when the Axis angle was \(0^{\circ}\) (when the plate was directly facing the Sun's rays). If we were to perform the action, we would observe a lower number of hits (for example, around 60 - 70, but the exact number depends on the Gizmo's simulation parameters). But the key concept is that a change in the axis angle (tilt) affects the angle of incidence of the Sun's rays, which in turn affects how many rays hit the plate (relating to the intensity of solar energy received, which is related to seasons on Earth).
• Answer: When the Axis angle is changed to \(40^{\circ}\), the number of rays hitting Plate M will be less than 100 (due to the more oblique angle of the Sun's rays hitting the plate).