Working out problems in Conquering the Physics GRE 3rd Edition by Yoni Kahn and Adam Anderson. Let's learn together :D
Sample Exam 1 Problem 001/100

Problem statement: A centrifuge can be used to simulate large gravitational forces. Consider a centrifuge consisting of an arm of length 4 meters, rotating about a fixed pivot at constant speed. What must this speed be to simulate a gravitational acceleration of 9g?