Question

the equation Y= -16t2 + 120 can be used to represent the fruit's height above the ground, where t represents time, in seconds, after she threw the apple. How long did it take the apple to hit the ground? Round your answer to the neares hundreth.

Answer 1

y = -16t^2 + 120

Let y = 0

Solve for t.

0 = -16t^2 + 120

-120 = -16t^2

-120/-16 = t^2

7.5 = t^2

sqrt{7.5} = sqrt{t^2}

2.7386127875 = t

We now round to the nearest hundredths, which means to 2 decimal places.

Answer: t = 2.74 seconds