A block starting from rest slides down the length of an 18 m plank with a uniform acceleration of 4.0 m/s. how long does it take for the block to reach the bottom?

Answer 1

Initial speed v_o = 0, Δx = 18 m, a = 4.0 m/s². To find time, use Δx = v_o t + 1/2 a t², 18 = 0 + 2.0 t², t² = 9.0, t = 3.0 s.