Bob and John are pulling in different directions. If Bob is pulling to the right with a force of 10N, and John is pulling to the left with a force of 12N

A) What is the net force acting on the box?

B) What direction the box will move

C) If the mass of the box is 4kg, what is the acceleration of the box?

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.