Let us consider two vectors A and B.
As per the question, the two vectors are perpendicular to each other.
Hence the angle between them 
We are asked to calculate the resultant of these two vectors.
As per parallelogram law of vector addition, the resultant of two vectors are-

[cos90=0]

This is the way by which we can add two perpendicular vectors.
Answer:
Rita and Katrina both followed similar paths into the Gulf.
Explanation:
If you saturated the solid it will turn into liquid and soon become an air
A = delta v over delta t delta v is calculated with final velocity less initial velocity then delta v is equals to 20 - 0 that is 20m/s and to calculate delta t is like delta v is final time less initial time as initial time always is 0 the delta t is equals to 10s then a = 20/10 then acceleration is 10m/s^2 (remember that is squared)