飞机以恒定的速度V沿水平方向飞行,距地面高为H,在飞行过程中释

飞机以恒定的速度V沿水平方向飞行,距地面高为H,在飞行过程中释放一枚炸弹,假设炸弹着地即刻爆炸,爆炸声向各个方向传播的速度为V0,空气阻力不计,求:

(1)释放炸弹后经多长时间飞行员可听到爆炸声。

(2)试分析飞机速度应满足什么条件时飞行员不可能听到爆炸声。

 

答案

(1)炸弹从A处落下做平抛运动,飞机继续做匀速运动,当炸弹到C处爆炸时,飞机在C处的正上方D,当爆炸声向四周匀速直线传播,传到B处时飞机恰也到达B处,如图,设炸弹抛出落地时间为t1,爆炸声从地面传到飞行员的时间为t2,则

                   (3分)

由几何关系有:(Vt22+H2=(V0t2)2          (3分)

而   t = t1+t2              (3分)

所以     (3分)

(2)当V≥V0时飞行员不可能听到爆炸声。(4分)

解析:略

 

相关题目

There are lots of places of interest _____ in our city. A. needs repairing  
There are lots of places of interest _____ in our city. A. needs repairing      B. needing repaired       C. needed repairing    D. needing to be repaired
在等腰△ABC中,AB=AC,O为不同于A的一点,且OB=OC,则直线A
在等腰△ABC中,AB=AC,O为不同于A的一点,且OB=OC,则直线AO与底边BC的关系为 A、平行             B、垂直且平分   C、斜交            D、垂
After my mother passed away,my dad tried even harder to stay healthy and acti
After my mother passed away,my dad tried even harder to stay healthy and active.Each morning he swam in the pool,and no matter how he felt,he would __36__swim one more lap(圈) than the previ
扩大基层民主,是完善发展中国特色社会主义民主政治的必
扩大基层民主,是完善发展中国特色社会主义民主政治的必然趋势和重要基础。目前,我国已初步建立起的基层民主自治体系主要包括           
下列作品、作者及作品中的人物搭配有误的一项:(    
下列作品、作者及作品中的人物搭配有误的一项:(     )   (1分) A、《从百草园到三味书屋》——鲁迅——《朝花夕拾》   B、《最后一课》—
—Excuse me, can you tell me the way to the zoo?  —Sorry, I’m new here.
—Excuse me, can you tell me the way to the zoo?  —Sorry, I’m new here. Please ask that policeman. He ______ know. A. can                                   
-- What a nice model boat! -- Think you.It _______ me a few days to make it.
-- What a nice model boat! -- Think you.It _______ me a few days to make it. A.paid           B.spent         C.took          D.tried
My views are too a__________for them and certainly not accepted;they just can’
My views are too a__________for them and certainly not accepted;they just can’t understand them!

最新题目