Working with acceleration in two dimensions makes use of the vector addition and subtraction methods from the previous lessons. Recall the formula for acceleration:
This formula can be used in twodimensional problems to find acceleration if you are given , , and .
Contents
Examples
Example 1
An airplane travelling at takes to change its velocity to . What is the average acceleration of the airplane over this time period?
Strategy:
 Use vector subtraction to find .
 Divide the result from Step 1 by to find .
Solution
Step 1 for this problem type is to find . This is the same type of problem we solved in the last lesson. If this step confuses you go back and review the 2D Vector Subtraction lesson.









For the second step, we will divide the above result by . We will be dividing a vector by a scalar. This operation (and multiplying a vector and a scalar) can be done in the same way as dividing (or multiplying) two scalars. This operation will result in a vector, with the same direction as the vector you started with.
Example 2
A race car driver experiences an average acceleration of starting at a velocity of . What is the velocity of the race car driver after ?
In this question, we are given acceleration and asked to find the final velocity. We can rearrange our formula to solve for this.
Strategy:
 Multiply by .
 Use vector addition to add and .
Solution









Example 3
Jon walks through Central Park at when he realizes he is being followed. He changes his speed in 1.2 seconds to . Find his acceleration.
Video Solution
Solution









Example 4
A car is travelling at , when it reaches a curve in the highway. if the car can accelerate at for 6.0 seconds, what is his final velocity?
Video Solution
Solution









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Example 5
Dr. McCoy is walking from his quarters to the bridge at (the Enterprise has a designated North). He is called to an emergency in the sick bay and accelerates at to get there, what is his velocity when he arrives 12 seconds later?
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Additional Resources
 Nelson Physics 12
 Pg. 28 – 29
Assignment Questions
Assignment 1:
 Pg. 29, #26
 Pg. 31, #14