Sue and Jenny kick a soccer ball at exactly the same time. Sue's foot exerts a force of 41.4 N to the north. Jenny's foot exerts a force of 102.7 N to the east. a) What is the magnitude of the resultant force on the ball? b) What is the direction of the resultant force (measured from East)?

Here you're simply adding two perpendicular vectors. If you want to know the magnitude of the resulting vector, use the distance formula, d=\sqrt{x^2 + y^2}. If you want to know the direction, remember that the angle is simply \theta = \tan^{-1} \left (\frac{y}{x} \right ), where y is the component perpendicular to the reference direction, and x is the component parallel (in this case they're asking for the angle measured from the East, so the North component would be y, and the East component would be x).

Can you take it from there?