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Topic 1.3: Practice Sheet — Free Fall

Name: _______________________________ Date: _______________ Period: ______

Directions: State your sign convention (which direction is positive) before starting each problem. Use g = 9.8 m/s². Show all work. Circle or box your final answer.

Warm-Up Level (straightforward, one-step)

  1. A ball is dropped from rest from a height of 19.6 m. Find the time it takes to hit the ground, and its velocity at impact.
  2. A ball is thrown straight up at 9.8 m/s. Find the time it takes to reach its maximum height, and the maximum height reached.

Standard Level (multi-step, matches typical AP Classroom depth)

  1. A rock is dropped from rest from a height of 78.4 m. Find the time to hit the ground and the velocity at impact.
  2. A ball is thrown straight up at 24.5 m/s. Find (a) the time to reach maximum height, (b) the maximum height, and (c) the total time in the air before it returns to its starting height.
  3. A ball is thrown straight up at 14.7 m/s. Using v² = vᵢ² + 2aΔx (with Δx = 0 for "returns to the starting height"), find its velocity the moment it returns to the height it was thrown from.

AP-Level (multi-part: calculate + justify/represent/predict-a-change)

  1. A ball is thrown straight up at 19.6 m/s from a rooftop 24.5 m above the ground. a) Find the maximum height the ball reaches above the ground. b) Find the ball's velocity the instant it hits the ground. c) Explain why you can't use the "time up equals time down" symmetry shortcut to quickly find this ball's total flight time, unlike a ball that returns to the exact height it was launched from.
  2. Two balls are dropped at the same instant from the same height — one is twice as heavy as the other. Ignoring air resistance, predict which ball hits the ground first. Justify your answer using the free-fall equations.

Keep this sheet — it's part of your semester study materials, same as your Concept Sheets.