## College Physics (4th Edition)

Published by McGraw-Hill Education

# Chapter 3 - Problems - Page 119: 114

#### Answer

(a) The force of friction acting on the crate is zero. (b) The force of friction acting on the crate is $18.4~N$ (c) The maximum acceleration that the truck can have without the crate starting to slide is $2.94~m/s^2$

#### Work Step by Step

(a) Since the speed is constant, the net force on the crate must be zero. Therefore, the friction force acting on the crate is zero. (b) We can find the mass of the crate: $mg = 180~N$ $m = \frac{180~N}{9.80~m/s^2}$ $m = 18.4~kg$ We can find the force of static friction acting on the crate: $F_f = ma = (18.4~kg)(1.0~m/s^2) = 18.4~N$ The force of friction acting on the crate is $18.4~N$ (c) We can find the maximum acceleration that the force of static friction can provide for the crate: $F_N~\mu_s = ma$ $mg~\mu_s = ma$ $a = g~\mu_s$ $a = (9.80~m/s^2)(0.30)$ $a = 2.94~m/s^2$ The maximum acceleration that the truck can have without the crate starting to slide is $2.94~m/s^2$

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.