Please help with questions 14,15,16,17

rs to questions 14)-16). A racecar, traveling at constant speed, makes one lap around a circular track of radius r in a time t . Note: The circumference of a circle is given by C = 2tr. 14) When the car has traveled halfway around the track, what is the magnitude of its displacement from the starting point? A) r B) 2r C) Ter D) 2Tr E) zero meters 15) What is the average speed of the car for one complete lap? A) 2r B) t C) t D t E) zero meters/second 16) Determine the magnitude of the average velocity of the car for one complete lap. A) 2r B) C) t 2 TT D) t E) zero meters/second 17) A stone is thrown straight up. What is its acceleration on the way up? A) 9.8 m/s2 upward B) 9.8 m/s2 downward C) zero D) not enough information