Physics, Efficiency. ?
2020-06-01 8:27 pm
A machine marked with the effect 5500W lifts a stone that weighs 450kg to 4.2m which takes 5.3 seconds. What is the machines efficiency?
回答 (1)
2020-06-01 8:40 pm
Take g = 9.81 m/s²
Output power
= m g h / t
= 450 × 9.81 × 4.2 / 5.3 W
= 3500 W
Efficiency = (3500/5500) × 100% = 64% (to 2 sig. fig.)
Output power
= m g h / t
= 450 × 9.81 × 4.2 / 5.3 W
= 3500 W
Efficiency = (3500/5500) × 100% = 64% (to 2 sig. fig.)
收錄日期: 2021-04-18 18:32:37
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20200601122757AAxq9cG