This document summarizes key concepts from a physics lecture: 1) Motion in two dimensions can be analyzed independently in the x and y directions using vectors like position, velocity, and acceleration. 2) Newton's laws of motion, including F=ma and Newton's Third Law, apply to both the x and y directions. 3) Relative motion problems can be solved by adding vector components of velocity relative to different reference frames.

2. Some Charts

6. Pulley, Incline and 2 blocks N A block of mass m 1 = 2.6 kg rests upon a frictionless incline as shown and is connected to mass m 1 via a flexible cord over an ideal pulley. What is the acceleration of block m 1 if m 2 = 2.0 kg? X – direction  F x = m a x : Block 1: T – m 1 g sin(30) = m 1 a 1x T = m 1 g sin(30) + m 1 a 1x Y – direction F y = m a y : Block 2: T – m 2 g = m 2 a 2y Note: a 1x = - a 2y Combine T – m 2 g = m 2 a 2y m 1 g sin(30) + m 1 a 1x – m 2 g = m 2 a 2y m 1 g sin(30) + m 1 a 1x – m 2 g = -m 2 a 1x m 1 a 1x +m 2 a 1x = m 2 g - m 1 g sin(30) (m 1 +m 2 ) a 1x = g (m 2 - m 1 sin(30)) 1.49 m/s 2 T m 2 g m 1 g T y x y x

14. A B C Think of a swimming pool on a cruise ship When swimming to the other side of the pool, you don’t worry about the motion of the ship ! Demo - bulldozer HW: swimmer x y