Tension and pulley problems  Forces and Newton's Laws
Tension and pulley problems
Lessons
Notes:
In this lesson, we will learn:
 What is tension?
 How to calculate tension
 Problem solving with tension
Notes:
 Tension is the force of a rope (or string, cable, etc.) pulling on an object.
 Tension is always a pulling force: a rope can't push!
 There is no formula for tension. Tension force acting on an object must be calculated from Newtons' second law.
 If the rope is assumed to be massless and nonstretchy, then the pulling force at either end of the rope must be equal in magnitude.
Newton's Second Law
 Tension is always a pulling force: a rope can't push!
$\Sigma \vec{F} = \vec{F}_{net} = m\vec{a}$
$\Sigma \vec{F}:$ sum of all forces, in newtons (N)
$\vec{F}_{net}:$ net force, in newtons (N)
$m:$ mass, in kilograms (kg)
$\vec{a}:$ acceleration, in meters per second squared $(m/s^{2})$
Newton's Third Law
For object A exerting a force on object B:
$\vec{F}_{A on B} =  \vec{F}_{B on A}$
$\vec{F}_{A on B}:$ force A is exerting on B, in newtons (N)
$\vec{F}_{B on A}:$ force B is exerting on A, in newtons (N)
Atwood Machine Equation
$a = g\frac{(m_{1}m_{2})}{(m_{1}+m_{2})}$
$a:$ acceleration of masses, in meters per second squared $(m/s^{2})$
$g:$ acceleration due to gravity, in meters per second squared ($m/s^{2}$)
$m_{1}:$ mass of first hanging mass, in kilograms (kg)
$m_{2}:$ mass of second hanging mass, in kilograms (kg)

Intro Lesson
Introduction to tension:

3.
Solving horizontal pulley problems with friction
Two boxes (8.00 kg and 4.40 kg) are tied together by a rope and hang from a pulley as shown. The coefficient of friction between the ground and the 8.00 kg box is 0.250.