Tycho Brahe's contribution to Kepler's Laws of Planetary Motion werea. his detailed and accurate observations of the planet's position. b. his observations of Jupiter's moons. c. a mathematical explanation of epicycles. d. a precise lunar calendar. the correct explanation of lunar phases.

Three archers each fire four arrows at a target. joe’s four arrows hit at points 10 cm above, 10 cm below, 10 cm to the left, and 10 cm to the right of the center of the target. all four of moe’s arrows hit within 1 cm of a point 20 cm from the center, and flo’s four arrows hit within 1 cm of the center. the contest judge says that one of the archers is precise but not accurate, another archer is accurate but not precise, and the third archer is both accurate and precise. which description applies to which archer? explain

Achemistry student needs of 40ml diethylamine for an experiment. by consulting the crc handbook of chemistry and physics, the student discovers that the density of diethylamine is 0.7 . calculate the mass of diethylamine the student should weigh out. round your answer to significant digits.

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)