Is (kr) an element a compound or a mixture?

Aboat radioed a distress call to a coast guard station. at the time of the call, a vector a from the station to the boat had a magnitude of 45.0 km and was directed 15.0° east of north. a vector from the station to the point where the boat was later found is = 30.0 km, 15.0° north of east. what are the components of the vector from the point where the distress call was made to point where the boat was found? in other words, what are the components of vector c = b - a?

Multiply 5.036×102m by 0.078×10−1, taking into account significant figures.

If the sun were to become a black hole, what would happen to earth? it is impossible to know the results. it would be sucked in very rapidly. it would continue in the same orbit. it would be sucked in very slowly. 3. which type of radiation us map the galaxy? visible light infrared 21 cm radio waves ultraviolet 4. henrietta leavitt found that the brighter appearing cepheids always had longer periods of light variation. this is an expression of what? period-luminosity relation luminosity function hertzsprung-russell diagram mass-luminosity relation 5. what is the surface or boundary of a black hole called? quasar active galaxy event horizon seyfert point 6. edwin hubble's discovery of a cepheid variable in the andromeda nebula led him to conclude that the nebula was what? a distant galaxy composed of hydrogen a supernova remnant the birthplace of stars 7. earth is near the center of the milky way galaxy. true false 8. how long does it take the sun to revolve around the center of the galaxy? two hundred thousand years two hundred million years two hundred years two hundred billion years