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## AP®︎/College Physics 1

### Course: AP®︎/College Physics 1>Unit 5

Lesson 4: Torque and angular acceleration

# Torque and angular acceleration

AP.PHYS: INT‑3.F (EU), INT‑3.F.1 (EK), INT‑3.F.1.1 (LO), INT‑3.F.1.2 (LO), INT‑3.F.1.5 (LO), INT‑3.F.2 (EK), INT‑3.F.2.1 (LO)

## Problem

A double pulley is free to rotate about its axis through its center. The radii of the two pulleys are R and 2, R. Two cords are wrapped in opposite directions on the pulleys and are attached to masses. As a result, the two tension forces acting on the pulley are equal and acting downwards as shown in the image below so that F, start subscript, 1, end subscript, equals, F, start subscript, 2, end subscript.
A diagram shows two concentric circles around a central point. The smaller circle has a radius of R. The larger circle has a radius of two R. From the left side of the smaller circle an arrow labeled F sub one points straight down. From the right side of the larger circle an arrow of the same length, labeled F sub two, points straight down.
When released from rest, what will be the direction of the angular acceleration?