How can we determine the direction of the acceleration on a free body diagram?

Question

I am asked to calculate the acceleration and the direction of it (vector) but I am not sure how to get the most accurate answer.

Answer 1

The direction of acceleration would be the direction of the net force of a free body diagram.

Since force is a vector, and force = mass * acceleration, and acceleration is a vector, the direction of the net or resultant force is the direction of the acceleration.