physics one dimensional motion

Question

a silly physics teacher drop a textbook a distance of 8m. how long will it take to hit the ground?

Answer 1

This is free-fall motion, so by the kinematic equations, 8 m = 0.5 gt² where t is the time it takes for the textbook to hit the ground. Solving for t, t = √(2 • 8 m/g) = √(16 m/9.8 m/s²) = 1.3 s.