## University Physics with Modern Physics (14th Edition)

We can find the magnitude of the force. $F = \sqrt{(-68.0~N)^2+(36.0~N)^2}$ $F = 76.9~N$ We can find the angle $\alpha$ above the (-x)-axis. $tan(\alpha) = \frac{36.0~N}{68.0~N}$ $\alpha = arctan(\frac{36.0~N}{68.0~N})$ $\alpha = 27.9^{\circ}$ We can find the angle $\theta$ between the force vector and the displacement vector. $\theta = 27.9^{\circ}+60.0^{\circ}$ $\theta = 87.9^{\circ}$ We can find the work done by the force. $W = F~d~cos(\theta)$ $W = (76.9~N)(48.0~m)~cos(87.9^{\circ})$ $W = 135~J$