passwella.
Menu

WAEC Mathematics 2016 Question 4

Question 4

Variation

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

  1. A.90 cm
  2. B.135 cm
  3. C.180 cm
  4. D.225 cm
Show the answer and explanation

Answer: C (180 cm)

Explanation

d = kt²: 45 = 9k so k = 5; then d = 5 × 36 = 180 cm.