A chemistry student (with nothing better to do than ride around on trains all day) is on a west bound train moving at a velocity of 15 m/sec towards the station. Before the two trains pass each other, what frequency will he hear from the train whistle from the physics student's train

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy.work depends on the square of the change in potential energy.work is equal to the negative of the change in kinetic energy.work is equal to the square of the change in kinetic energy