Two converging lenses with the focal lengths f 1 = 0.2 m and f2 = 0.4 m are positioned at a distance f1 + f2 to each other. such arrangements are called "beam expanders" and are often used in laser technology
a) what is the expansion ratio w2 / w1?
one of the two converging lenses is now to be replaced by a diverging lens, with the same expansion ratio w2 / w1 to be achieved.
b) which of the two lenses is that and what is the focal length of the dissipation lens?
c) what is the distance of the lenses now?

During spring semester at mit, residents of the parallel buildings of the east campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. a balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. assume that the stretching of the hose obeys hooke's law with a spring constant of 89.0 n/m. if the hose is stretched by 5.80 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length? unitst 3 number-1497 the tolerance is +/-5% open show work click if you would like to show work for this question:

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Acombination reaction is when two or more combine to form one product. a decomposition reaction is when a substance breaks down into two or more simpler substances in a chemical reaction.