Question

This is a depiction of 2 forces acting on a puck (top view). Which direction would a 3rd force have to be to balance the forces? [picture below]

Answer 1

The 3rd force would have to have components the same magnitude as F1 and F2, but in the opposite direction. A little thought will (hopefully) tell you that the combination of F1 and F2 will produce a combined force going up and to the right, so F3 will have to be applied ...

Answer 2

to the left ?

Answer 3

to the left, and somewhat down, too...you have to cancel out the force going up (F1)

Answer 4

That's the combined F1+F2

Answer 5

F3 will be equal in length to F1+F2, but in the opposite direction. I could also construct it by making two force vectors equal in length to F1 and F2, but again in the opposite directions, then combining those two

Answer 6

Not the best drawing, but hopefully you get the idea