Give the right answer of given question-

Question- If a particle moves with constant speed, and then the velocity and acceleration vectors are orthogonal.

Part 1- Give an example of this fact where the velocity vector is not constant. Be sure to show that your velocity vector satisfies both conditions. (For extra credit, show that the above fact is true in general.)

I need help to compute the above question. Be sure to explain that your velocity vector satisfies both conditions. For additional credit, show that the above fact is true in general.