A mother pushes a baby stroller 10 meters by applying 40 newtons of force. how much work was done?

Based on the situation above the the work done was 400 Joules. Q = FS cos (theta) is the so-called work function. It's important to learn the work physics; you'll see it over and over in science/physics class. Theta is the angle between the force vector F and the distance vector S. In your problem we assume theta = 0, the two vectors were assumed aligned.