A concave mirror is used in automobiles to have a clear view of a traffic behind give reason

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

The density of a liquid could be found by using

True or false: the cycle of seasons on the earth is caused by the tilt of the earth on its axis toward and away from the sun.