Which of the following types of stars started out on the main sequence with the largest initial mass? In Graph A, the curve peaks at 800 nm, in the red section of the visible light spectrum. In Graph B, the curve peaks at 550 nm, in the green section of the visible light spectrum. In Graph C, the curve peaks at 450 nm, in the blue section of the visible light spectrum. In Graph D, the curve peaks at 300 nm, in the violet section of the visible light spectrum.
PLZ HELP
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Amira pulls a 3 pound wagon 4 feet. how much work has she done?

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s. part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.

Consider each of the electric- and magnetic-field orientations given next. in each case, what is the direction of propagation of the wave? a)\vec ein the +xdirection,\vec bin the +ydirection. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction b)\vec ein the -y direction,\vec bin the +x choose+ x direction- x direction+ y direction- y direction+ z direction- z direction c)\vec ein the +z direction,\vec bin the -x direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction d)\vec ein the +y direction,\vec bin the -z direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction