A wall clock has a minute hand with a length of 0.49 m and an hour hand with a length of 0.26 m. Take the center of the clock as the origin, and use a Cartesian coordinate system with the positive x axis pointing to 3 o'clock and the positive y axis pointing to 12 o'clock. Express the position vectors of the tip of the hour hand () and the tip of the minute hand () at the following times. (a) 12:00 = ( m)