v车=54km/h=15m/s,
汽车2s前进的路程:s车= v车t =15m/s x 2s=30m
鸣笛声2s经过的路程:s声= v声t=340m/s*2s=680m,
听到回声处汽车与山崖的距离:L= (s声-s车)/2=(680m-30m)/2=325m,
答:听到回声处汽车距离山崖有325米.
司机鸣笛地点距离山:L’=(s声+s车)/2=(680m+30m)/2=355m,
v车=54km/h=15m/s,
汽车2s前进的路程:s车= v车t =15m/s x 2s=30m
鸣笛声2s经过的路程:s声= v声t=340m/s*2s=680m,
听到回声处汽车与山崖的距离:L= (s声-s车)/2=(680m-30m)/2=325m,
答:听到回声处汽车距离山崖有325米.
司机鸣笛地点距离山:L’=(s声+s车)/2=(680m+30m)/2=355m,