[填空题]
A ball is dropped from the tou1/;yf0ouzx8g ku a g+cf y4l05vt*p jp of the Eiffel Tower, 32 wlibk.d;g .a24 metres from the ground. The ball falls a distance of 4.9 metres during the first second, 14.7 metres during the next second, 24.5 metw.2gkbli; a d.res during the third second, and so on. The distances that the ball falls each second form an arithmetic sequence.
1.1.Find d, the common difference of the sequence.
d= .
1.2.Find $u_5$ , the fifth term of the sequence.
$u_5$= m.
2.Find $S_6$, the sum of the first 6 terms of the sequence.
$S_6$= m.
3.Find the time the ball will take to reach the ground. Give your answer in seconds correct to one decimal place.
we obtain n ≈ seconds
Assuming the ball is dropped another time from a much higher height than of the Eiffel Tower,
4.find the distance the ball travels from the start of the 10th second to the end of the 15th second.
we get S= m.
The Eiffel Tower in Paris, France was opened in 1889, and 1.9 million visitors ascended it during that first year. The number of people who visited the tower the following year (1890) was 2 million.
5.Calculate the percentage increase in the number of visitors from 1889 to 1890. Give your answer correct to one decimal place.
% increase= %.
6.Use your answer to part (e) to estimate the number of visitors in 1900, assuming that the number of visitors continues to increase at the same percentage rate.
$v_{12}$= million.
