Alight source whose surface is approximated by a circle with a radius of 3 cm is located 2 m from a screen. if an aperture with a 1-cm radius is placed between the source and the screen, how far from the screen can the aperture be placed without affecting the irradiance in the screen at the center of the patch of light passed by the aperture? if the aperture is moved twice as far from the screen, what will be the irradiance at the center of the patch as a fraction of the unobstructed irradiance?

b. a lightning bug, plug of grass, and a worm

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.