# Arizona State University| PHY 121: Univ Physics I: Mechanics|Homework 1-1| Problem 2

Learning Goal:

To practice Tactics Box 1.2 Vector Subtraction.
Vector subtraction has some similarities to the subtraction of two scalar quantities. With numbers, subtraction is the same as the addition of a negative number. For example, 53 is the same as 5+(3). Similarly, A⃗ B⃗ =A⃗ +(B⃗ ). We can use the rules for vector addition and the fact that B⃗ is a vector opposite in direction to B⃗  to form rules for vector subtraction, as explained in this tactics box.

To subtract B⃗  from A⃗  (Figure 1), perform these steps:

1. Draw A⃗ .
2. Draw B⃗  and place its tail at the tip of A⃗ .
3. Draw an arrow from the tail of A⃗ to the tip of B⃗ . This is vector A⃗ B⃗ .
Part A
Draw vector C⃗ =A⃗ B⃗  by following the steps in the tactics box above. When drawing B⃗ , keep in mind that it has the same magnitude as B⃗  but opposite direction.
Part B
Draw vector F⃗ =D⃗ E⃗ by following the steps in the tactics box above. When drawing E⃗ , keep in mind that it has the same magnitude as E⃗  but opposite direction.