This is multiple choices. Can u help me?

17. What is the angle between the vectors A and -A when they are drawn from a common origin? a. 270 b. 180 C. 90 d. 0 18 Which of the following is a vector quantity? a. the age of the earth b. the mass of a football c. the number of people attending a baseball game d. the earth's pull on your body 19 What is the minimum number of vectors with equal magnitudes whose vectorsum can be zero? a. 1 b. 2 C. 3 d. 4 20 For which of the following situations will the path length equal the magnitude of the displacement? a. A ball is rolling in the floor. b. A jogger is running around a circular path. C. A train travel 5 miles east; and then itstops and travels 2 miles west. d. A ball rises and falls after being thrown straight up from the earth's surface. 21 In which of the following situations does the car have a westward acceleration? a. The car travel westward at constant speed. b. The car travels eastward and speeds up. c. The car travels eastward and slows down. d. The car travels westward and slows down. 22 For a uniform motion, which of the following quantities must be zero? a. displacement b. speed c. velocity d. acceleration The acceleration of a stone thrown upward is a. zero until it reaches the highest point in its motion b. smaller than that of a stone thrown downward c. the same as that of a stone thrown down ward d. greater than that of a stone thrown downward 24 A stone is thrown upward from a roof at the same time as an identical stone is dropped from there. Neglecting air resistance, the two stones a. reach the ground at the same time b. have the same velocity when they reach the ground c. reach the ground with zero velocity d. have the same acceleration when they reach the ground 25 A feather is dropped at a certain height. At the same height with the feather, a cotton and ball are also dropped. If no air is present in the system, which of these three objects fall to the ground first? a. feather b. cotton c. ball d. feather, cotton, and ball 26 Ball A is thrown horizontally, and ball B is dropped from the same height at the same moment a. Ball A has the greater speed when it reaches the ground b. Ball B has the greater speed when it reaches the ground c. Ball A reaches the ground first d. Ball B reaches the ground first