49) Two crates, of mass 65 kg and 125 kg , are in contact and at rest on a horizontal surface as shown in the figure on the right. A \( 650-\mathrm{N} \) force is exerted on the \( 65-\mathrm{kg} \) crate. If the coefficient of kinetic friction is 0.18 , calculate (a) the acceleration of the system, and (b) the force that each crate exerts on the other. (c) Repeat with the crates reversed. Answers: a) \( 1.7 \mathrm{~m} / \mathrm{s}^{2} \)
b) 430 N
c) \( 1.7 \mathrm{~m} / \mathrm{s}^{2}, 220 \mathrm{~N} \)
