# Chapter 7 - Newton's Third Law - Exercises and Problems - Page 186: 15

(a) A force of 20 N pulls forward on the ice. (b) A force of 21 N pulls forward on the rope.

#### Work Step by Step

(a) Let $F_i$ be the force that pulls forward on the ice. We can find the magnitude of $F_i$. Let $m_i$ be the mass of the ice. $F_i = m_i~a$ $F_i = (10~kg)(2.0~m/s^2)$ $F_i = 20~N$ A force of 20 N pulls forward on the ice. (b) Let $F_r$ be the force that pulls forward on the rope. We can find the magnitude of $F_r$. Let $m_i$ be the mass of the ice. Let $m_r$ be the mass of the rope. $F_r = (m_i+m_r)~a$ $F_r = (10~kg+0.50~kg)(2.0~m/s^2)$ $F_r = 21~N$ A force of 21 N pulls forward on the rope.

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.