問題詳情
28、Your heart beats at the rate of 70 times per minute, each beat pumping about 60 cm3 of fluid against a pressure of 120 mmHg. How much expansion work does the heart do in a day? (Note: The heart work does much more work than this. The heart muscles are contracting, the blood is accelerated, and there are frictional losses and other factors involved.)
(A) 9.68X101 J
(B) 9.68x102 J
(C) 9.68x103 J
(D) 9.68x104 J
參考答案
答案：D
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)
用户評論
【用戶】高昇賢
【年級】小三上
【評論內容】1atm = 760 mmHg、1atm·L = 101.39JWday = P△V = (120/760)atm×(60/1000)L×101.39J/atm·L×70次/min×60min/hr×24hr/day = 96822J = 9.68×104 J/day