[填空题]
Peter is playing on a swing during a sr9rmn e/5-y;y 6 zxc(yr2dkj 8ffc6kfchool lunch break. The h),e 1dwefu zi:(yp nc7eight of the first swing was 2 m and every subsequent swing was 84 % of the previous one. Peter's friend, Ronald, yew(fu i,ce7:)d p1nzgives him a push whenever the height falls below 1 m.
1.Find the height of the third swing.
we find $u_3$ ≈ m.
2.Find the number of swings before Ronald gives Peter a push.
Hence the swing needs a push after swings.
3.Calculate the total height of swings if Peter is left to swing until coming
to rest.
$S_∞$= m.
