Practice!

Sample Problem

In the diagram below, M = 10 kg and m = 5 kg. The coefficient of kinetic friction between m and the tabletop is 0.5. What is the acceleration of the blocks? . Round to the nearest tenth.

m/s2

Solution

ma = T – f

Ma = Mg – T

f = μ × N = μ × mg

Ma + ma = Mg – f

Ma + ma = Mg – μmg

a = (Mg – μmg) ÷ (M + m)

a = (10 × 9.8 – 0.5 × 5 × 9.8) ÷ (10 + 5)

a = 4.9 m/s2