Question

Question #aaab8

Answer 1

Here's an alternative method you can use to solve this problem.

Explanation:

You can determine the distance covered by your ball in its thirds seconds of flight by subtracting what it travelled in 2 seconds from what it travelled in 3 seconds.

`h_"third second" = h_3 - h_2`

Two seconds after its launch, the object covered

`h_2 = v_0 * t + 1/2 * g * t^2`

`h_2 = 4"m"/cancel("s") * 2cancel("s") + 1/2 * 10"m"/cancel("s"^2) * 2^2cancel("s"^2) = "28 m"`

Three seconds after its launch, the ball covered

`h_3 = 4"m"/cancel("s") * 3cancel("s") + 1/2 * 10"m"/cancel("s"^2) * 3^2cancel("s"^2) = "57 m"`

Therefore, the distance it covered in its third seconds of flight is

`h_"third second" = 57 - 28 = color(green)("29 m")`