Question

A child is given a push on a swing.Each time she swings back a little less, according to the equation d=2(0.85)^n , where d is the horizontal distance, in metre, from her position after n complete swings. After how many swings will the distance from rest be less than 15cm.

Answer 1

2(0.85)^n < 0.15

solve for n. Remember n is a positive integer

Answer 2

n=1.95