physics
posted by mo .
the earthis moving around the sun in a circular orbit of radius 1.5*10^11. it makes one revolution per year.find the angular speed of earth in radian/sec, and the tangential speed of earth using the formula v=r.w , and tangetial speed ?

angular speed in radians/sec
w = (2 pi radians)/(# of seconds in 1 year)
Once you have w, you can compute the tangential speed with the formula given. You have given value of r but you did not say if the number is km or meters.