Lesson: The Work–Energy Principle Mathematics
In this lesson, we will learn how to use the work–energy principle to solve problems of motion of a particle.
A particle of mass 150 g was projected at 13 m/s across a horizontal plane. It decelerated uniformly at 2 m/s2. Find the change in its kinetic energy in the first 4 seconds of motion.
A body of mass 96 kg was moving in a straight line at 17 m/s. A force started acting on it in the opposite direction to its motion. As a result, over the next 96 m, its speed decreased to 11 m/s. Using the work-energy principle, determine the magnitude of the force.
A body of mass 400 g was projected at 4 m/s vertically downward from a point 5 m above the ground. Use the work–energy principle to calculate the body’s kinetic energy when it was about to hit the ground. Take .