Tension, Teeth, and Force??? The drawing below shows an elastic cord attached to two back teeth and stretched across a front tooth. The purpose of this arrangement is to apply a force to the front tooth. (The figure has been simplified by running the cord straight from the front tooth to the back teeth.) If the tension in the cord is 1.3 N, what are the magnitude and direction of the force applied to the front tooth? I'm completely stumped, I've tried every equation I know of. I'm sure the answer is obvious but right now I think I'm thinking too hard. Help please?