I've spent hours on this question: A truck of mass 4500 kg is traveling in a fog due north at 20 m/s. Suddenly, at point A, the driver notices a wall straight ahead. He makes a sharp right turn along path AB, which is one-quarter of a circle of 50 m radius. He does this without any change in speed. From B to C he slows down uniformly, arriving at C with a velocity of 14 m/s [E]. The trip from A to C takes 5.8 seconds. I made a diagram: Calculate: (a) the average acceleration of the truck from A to C, (b) the average velocity of the truck as it travels from A to C. I figured to find average velocity first, so I drew a line from point A to point C, and using the the equation of d=((V1-V2)/2)xT, I found the distance between B and C, and calculated the displacement from A to C. Then I divided it by change in Time (5.8s) to find velocity, giving me 16.53 m/s. To find acceleration, I think I need to use the equation a=v^2/R. However, there is no radius since I extended the displacement. Is what I'm doing correct? I desperately need help and can't determine if what I'm doing is right or wrong.