想問下面兩題...請詳細寫出所用公式都steps...識一題都可以答...THANK YOU
Q1:A train has a uniform acceleration of 0.2m/s² along a straight track.calcurlate
(A)the velocity after an interval of 16s from standstill,
(b)the time required to attain a velocity of 14m/s,
(C)the distance traceled from standstill intil the train attains a velocity of 14m/s,
(D)the time taken for the velocity to increase from 8.5 m/s to 14m/s and the distance traveled during that time
Q2:
不明白的stress問題
A steel bar of 20mm diameter is subjected to a tensile force of 1000kN. Determine the tensile stress of the steel bar.
SCIENCE 20分
2008-09-21 1:01 am
回答 (2)
2008-09-21 3:50 am
✔ 最佳答案
(A)apply (v-u)/t=a(v-0)/16=0.2
v=3.2m/s
(B)apply (v-u)/t=a
(14-0)/t=0.2
t=70s
(C)from (B) t=70
apply s=ut+1/2at^2
s=0+1/2(0.2)(70)^2
s=490m
(D)apply (v-u)/t=a
(14-8.5)/t=0.2
t=27.5s
apply s=ut+1/2at^2
s=0+1/2(0.2)(27.5)^2
=7.5625m
Q2...會考好似冇,我also冇學過,sor
參考: me
2008-09-21 3:47 am
Q1
(a)16 x 0.2 = 3.2m/s
(b)14 / 0.2 = 70 s
(a)16 x 0.2 = 3.2m/s
(b)14 / 0.2 = 70 s
收錄日期: 2021-04-26 17:30:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080920000051KK01632