4 m. Many students mistakenly compute displacement ((=0) from t=0 to t=4) and get 0 m—wrong.
: Solving expressions where the power is zero (e.g., Equations : Freefall Mathematics Velocity Book 4 Answers
Leo had solved (a) easily: v = u + at → 0 = 30 – 10t → t = 3 seconds. Part (b): s = ut + ½at² → 30×3 – 5×9 = 90 – 45 = 45 m above cliff. He even got part (c) mostly right until the quadratic spat out t = 7 seconds and he forgot to add the initial 3 seconds, writing 7 instead of 10 . A simple error. But Mr. Hargrove didn’t grade simple errors kindly. He wrote “Incomplete conceptual integration” in red ink that bled through the page. Part (b): s = ut + ½at² →