7. When the compressor of a refrigerator runs, it performs 300 J of work per second' If the compressor runs for 15 ME per day and 1k W-h costs $0.16, how much would you spend to run the refrigerator for 30 days? Two people are in the weightlifting room. Ken lifts a 45.0 kg barbell over his head 20 times in 60.0 s. Doug lifts the same barbell over his head 20 times in 10.0 s. a) Which person does the most work? (show all the wok) b) Which person delivers the most power? (show all the wok)