Answer
(a) $W = 0.20~J$
(b) $v = 2.98~m/s$
Work Step by Step
(a) We can find the work done by the wind as;
$W = F\cdot \Delta r$
$W = F_x~\Delta r_x+F_y~\Delta r_y$
$W = (4.0\times 10^{-2}~N)(2.0~m)+(-6.0\times 10^{-2}~N)(-2.0~m)$
$W = 0.20~J$
(b) The kinetic energy will be equal to the work done by the wind. Therefore;
$KE = W$
$\frac{1}{2}mv^2 = W$
$v^2 = \frac{2W}{m}$
$v = \sqrt{\frac{2W}{m}}$
$v = \sqrt{\frac{(2)(0.20~J)}{0.045~kg}}$
$v = 2.98~m/s$
