Question

A falling object travels a distance given by the formula d=3t+5t2, where d is measured in feet and t is measured in seconds. How many seconds will it take for the object to travel 84 feet?

Answer 1

4.52secs

Explanation:

Given the height of a falling object expressed as;

d=3t+5t^2

If the object travel 84 feet, we are to find the time t it takes to travel. On substituting;

84 = 3t+5t^2

3t+5t^2 - 84 = 0

t = -5±√25-4(3)(-84)/2(3)

t = -5±√25+1008/6

t = -5±32.14/6

t = -5+32.14/6

t = 27.14/6

t = 4.52 secs

Hence it will take 4.52secs for the object to travel 84feet