A train car with one seater passenger rolls down a steep hill with acceleration a. The person gets scared, and runs frantically back-and-forth inside the train. what is the magnitude of the acceleration of the center of mass of the train person system while the person runs?

In physics the desire of an object to keep doing what it is doing is termed?

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.