End of unit questions and problems

1. A vector drawn 15 mm long represents a velocity of 30 m/s. How long should you draw a vector to represent a velocity of 20 m/s? 

2. A vector that is 1 cm long represents a displacement of 5 km. How many kilometers are represented by a 3 cm vector drawn to the same scale? 

3.   Describe how you would add two vectors graphically.