Abird is placed in a chamber with two pecking keys. the green one provides food on a vi60 sec (variable interval of 60 seconds) schedule and the yellow key provides food on a vi180 sec schedule. according to the matching law, what is the percentage of time the bird pecks the green key?

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

What are some properties of transverse waves?

What happens when you slowly pulled the carboard?