Remember, work happens when the force that is applied to the object moves the object in the same direction as the force. Here is an example to show what this means. Let’s say you reach down with your arms and pick up a bag of groceries off the floor. Your arms are doing work, as the upward force applied in picking up the groceries moved the groceries in an upward direction. In a scientific sense, would you be doing work if you then carried the groceries in your arms across the room to the cupboard?The answer is no. Your arms are still applying an upward force to hold the groceries up, but the direction the groceries are going is across the floor, not in the direction of the force your arms are exerting. Although your whole body is doing work to carry itself across the room, you are not doing work to carry the groceries.
