# The distance d through which a stone falls from... - WAEC Mathematics 2016 Question

The distance, d, through which a stone falls from rest varies directly as the square of the time, t, taken. If the stone falls 45cm in 3 seconds, how far will it fall in 6 seconds?

A

90cm

B

135cm

C

180cm

D

225cm

**correct option:**c

d \(\alpha\) t

d = t

where k is a constant. d = 45cm, when t = 3s; thus 45 = 3

k = \(\frac{45}{9}\) = 5

thus equation connecting d and t is d = 5t

when t = 6s, d = 5 x 6

= 5 x 36

= 180cm

^{2}d = t

^{2}kwhere k is a constant. d = 45cm, when t = 3s; thus 45 = 3

^{2}x tk = \(\frac{45}{9}\) = 5

thus equation connecting d and t is d = 5t

^{2}when t = 6s, d = 5 x 6

^{2}= 5 x 36

= 180cm

**Please share this, thanks:**

### Add your answer

No responses