[填空题]
Georgia is on vacation8.4ufr g2ubbtds/x9 h t6 qsc iq-sh7z4p*9ien9;2od6lz3 ixw6k*hdai gf/st71ja f in Costa Rica. She is in a hot air balloon over a lush jungle in Muelw f3ls i*zkoftngjh6/d2x aa6i719;dle.
When she leans forward to see the treetops, she accidentally drops her purse. The purse falls down a distance of 4 metres during the first second, 12 metres during the next second, 20 metres during the third second and continues in this way. The distances that the purse falls during each second forms an arithmetic sequence.
1.1.Write down the common difference, d, of this arithmetic sequence.
d= .
1.2.Write down the distance the purse falls during the fourth second.
$u_4$= m.
2.Calculate the distance the purse falls during the 13th second.
$u_{13}$= m.
3.Calculate the total distance the purse falls in the first 13 seconds.
$S_{13}$= m
Georgia drops the purse from a height of 1250 metres above the ground.
4.Calculate the time, to the nearest second, the purse will take to reach
the ground.
n≈ seconds.
Georgia visits a national park in Muelle. It is opened at the start of 2019 and in the first year there were 20000 visitors. The number of people who visit the national park is expected to increase by 8% each year.
5.Calculate the number of people expected to visit the national park in 2020.
$v_2$= .
6.Calculate the total number of people expected to visit the national park by the end of 2028.
$S_{10}$= .
