Optics True or False question?

True or False? Why?





A cloud casts a shadow on the ground. If you could measure the actual size of the cloud and the size of the shadow you would find the size of the shadow to be considerably larger than the size of the cloud, especially if the cloud is at a high altitude.Optics True or False question?
the correct answer is:





sort of:





If it's a very, very sunny day, and the cloud is illumunated by the sun overhead, then the shadow is every-so-slightly larger, but pretty much the same size.





It gets a bit bigger if the sun is at an angle.





If it's a day when light is dispersed by clouds above, the cloud will have a partial shadow that is much, much larger, but a total shadow that is small or nonexistant. I define a partial shadow as a spot of ground that gets some of the light, but not all. Full shadow, means all the overhead light is blocked.Optics True or False question?
The source of light is far away, so the rays can be assumed to be parallel. Now you have to consider temperature/density/humidity/size of the cloud/highth of the cloud/curvature of the earth/ /index of refraction of the atmosphere above and below the cloud. All things being negligible, should be the same size
True.





Point a lamp towards a wall. Place your hand in front of the lamp, and move it closer and further away from it. Notice the change in the size of the shadow.





(Imagine some lines between the light source, and your hand, and follow them each to the wall. It should become evident)
In the morning or evening or anytime in winter, sure it's possible due to the perspective, in the same way that it's easy for your shadow to be much taller than you. With the sun directly overhead, the difference would be minimal; the shadow area would technically be larger that the cloud's horizontal cross-sectional area, but I wouldn't say ';considerably';. The distance from the sun to the Earth is so much greater than the distance from the cloud to the ground that the sun's rays at opposite ends of the cloud are very close to parallel.
I'm not sure about considerably larger but it should be slightly larger. The closer an object is to a light source, the more light it blocks. Consider though that a cloud, even at a high altitude, is not much closer to the sun than the Earth's surface when you consider the total distance of the earth's surface to the sun. it would only be a tiny fraction of a percent closer to the sun than the surface.





I'd have to say False