please answer these questions i am confused on all of them

1. (a) What is the difference between a vector and a scalar? Give a physical example of each. (b) How can you determine whether or not two vectors are orthogonal? (c) How can you determine whether or not two vectors are parallel? (d) How can you determine whether or not three vectors with a common initial point lie in the same plane in 3-space? 8. Let u = (3,5, -1) and v = (2, -2, 3). Find (a) 2u + 5v (b) (c) lull (d) |ju - vil. 9. Let a = ci + j and b = 4i + 3j. Find c so that (a) a and b are orthogonal (b) the angle between a and b is 7/4 (c) the angle between a and b is 7/6 (d) a and b are parallel. tude from vertex C to side AB. 16. True or false? Explain your reasoning. (a) If u . v = 0, then u = 0 or v = 0. (b) If u X v = 0, then u = 0 or v = 0. (c) If u . v = 0 and u X v = 0, then u = 0 or v = 0