Problem: Robert has just bought a new model rocket, and is trying to measure its flight characteristics. The rocket engine package claims that it will maintain a constant thrust of 12.6 N until the engine is used up. Robert launches the rocket on a windless day, so that it travels straight up, and uses his laser range-finder to measure that the height of the rocket when the engine cuts off is 21.2 m. He also measures the rocket\'s peak height, which is 25.7 m.

Part A: If the rocket has a mass of 0.763 kg, how much work is done by the drag force on the rocket during its ascent?

I need help to find how much work is done by the drag force on the rocket during its ascent.