Halliday, Resnick & Walker — Force and Motion–II: Problem 26_M_GO

Figure 6.21 shows three crates being pushed over a concrete floor by a horizontal force \(\vec{F}\) of magnitude \(440 \text{ N}\). The masses of the crates are \(m_1 = 30.0 \text{ kg}\), \(m_2 = 10.0 \text{ kg}\), and \(m_3 = 20.0 \text{ kg}\). The coefficient of kinetic friction between the floor and each of the crates is \(0.700\). (a) What is the magnitude \(F_{32}\) of the force on crate 3 from crate 2? (b) If the crates then slide onto a polished floor, where the coefficient of kinetic friction is less than \(0.700\), is magnitude \(F_{32}\) more than, less than, or the same as it was when the coefficient was \(0.700\)?