41. cannonball has just been shot out of a cannon aimed 45above the horizontal . Drag cannot be neglected . what force

When you go to ask a qustion there will be a picture of a paper clip looking thing and then it will pop up your files and you click on the imajes and then you up load it

Planck decided to assume that atoms could only vibrate at certain frequencies that were whole numbers eg 2f, 3f and so on. others used to think that atoms vibrate continuously

Iwould think it is temperature, silica, oxides (gases)

Current supplied to consumers from generating plants like coal power plant, nuclear power plant, geothermal and others are in form of alternating current instead of direct current because it can be transported easily in a long distance. also, the alternating current has a wide range of frequency and the amount or energy can be increased or decreased.