Which type system allows energy to enter or leave the system, but does not allow matter to cross into or out of the system?

Juan has a retail business selling skateboard supplies he maintains large stockpiles of every item he sells in a warehouse on the outskirts of town he keeps finding that he has to reorder certain supplies all the time but others only once a year how can he solve this problem?

Consumers who participate in the sharing economy seem willing to interact with total strangers. despite safety and privacy concerns, what do you think is the long-term outlook for this change in the way we think about interacting with people whom we don't know? how can businesses to diminish worries some people may have about these practices?

Qwest airlines has implemented a program to recycle all plastic drink cups used on their aircraft. their goal is to generate $7 million by the end of the recycle program's five-year life. each recycled cup can be sold for $0.005 (1/2 cent). a. how many cups must be recycled annually to meet this goal? assume uniform annual plastic cup usage and a 0% interest rate. b. repeat part (a) when the annual interest rate is 12%. c. why is the answer to part (b) less than the answer to part (a)?