Chapter 7, Problem 8OQ

In a laboratory model of cars skidding to a stop, data are measured for four trials using two blocks. The blocks have identical masses but different coefficients of kinetic friction with a table: μ_k = 0.2 and 0.8. Each block is launched with speed v_i = 1 m/s and slides across the level table as the block comes to rest. This process represents the first two trials. For the next two trials, the procedure is repeated but the blocks are launched with speed v_i = 2 m/s. Rank the four trials (a) through (d) according to the stopping distance from largest to smallest. If the stopping distance is the same in two cases, give them equal rank. (a) v_i = 1 m/s, μ_k = 0.2 (b) v_i = 1 m/s, μ_k = 0.8 (c) v_i = 2 m/s, μ_k = 0.2 (d) v_i = 2 m/s, μ_k = 0.8