Which item is an example of a primary source? a. an academic paper analyzing john f. kennedy's presidency b. a transcript of a presidential speech c. a textbook about american foreign policy d. a newspaper article reflecting on the anniversary of the end of the cold war

1. explain how you calculate the net force in any direction on the box. 2. suppose an upward force of 15n is added to the box. what will be the net vertical force on the box? 3. what force could be applied to the box to make the net force in the horizontal direction zero? explain. 4. suppose a force of 25n to the right is added to the box. what will be the net force to the right?