Q: A 25.0 kg grindstone disc with a 0.250 m radius ( r ) rotates with an angular speed ( ω ) of 30.0 rad/s. When power to the disc is shut off, it decelerates and comes to rest over the course of 20.0 s. When the grindstone is shut off, a speck of dustContinue reading “AP PHYSICS: Rotational Kinematics”
Tag Archives: angular velocity
INTRODUCTION TO ELECTRONICS: DC Motors
We have seen how a conducting wire moving with respect to an electric field ( B ) will experience forces upon its electrons. Consider the diagram below: Due to the proper ( perpendicular ) alignment of the loop and magnetic field, the maximum amount of DC current will be produced; however the voltages and currentsContinue reading “INTRODUCTION TO ELECTRONICS: DC Motors”
ENERGY AND MOMENTUM: Conservation of Linear and Angular Momentum ( Part 1 )
Q: A ( 1kg ) ball of clay moving with a velocity ( vbi ) collides and sticks to the end of a ( 120cm ) rod of uniform mass ( 2kg ). Assuming that the ball and rod are at rest upon a frictionless surface: ( a ) Where is the new center ofContinue reading “ENERGY AND MOMENTUM: Conservation of Linear and Angular Momentum ( Part 1 )”
ENERGY AND MOMENTUM: Parallel Axis Theorem/Moment of Inertia of a Rod
The moment of inertia ( I ) is the rotational equivalent of mass possessed by an object. This proclamation, however, comes with a caveat: massive objects are not created equal. Different objects of equal mass have differing abilities to resist changes in rotational motion. Additionally, the location of an object’s axis of rotation influences itsContinue reading “ENERGY AND MOMENTUM: Parallel Axis Theorem/Moment of Inertia of a Rod”
ROTATIONAL MOTION: What Distance Separates Two Projectiles Revolving Around a Common Center of Mass?
Q: Two projectiles separated by distance ( dt ) revolve around their center of mass ( cm = ½ dt ). Each projectile has a mass ( m ) of 4.81 x 1020 kg, and they have an instantaneous rotational speed ( ⍵ ) of 1.25 x 10-10 rad/s relative to the center of mass.Continue reading “ROTATIONAL MOTION: What Distance Separates Two Projectiles Revolving Around a Common Center of Mass?”
FORCE AND ACCELERATION: Relative Velocity of Satellites in Orbit
Q: A satellite circles a planet with a tangential velocity of 1.70 x 104 m/s. The orbital radius ( r1 ) is 5.25 x 106 m. A second satellite of equal mass revolves around the same planet with an orbital radius ( r2 ) of 8.60 x 106 m. What is the orbital speed ofContinue reading “FORCE AND ACCELERATION: Relative Velocity of Satellites in Orbit”
ROTATIONAL MOTION: Rotational Inertia
Q: A student sits atop a freely rotating stool holding two dumbbells, each of which has a mass of 3.09 kg. When the student’s arms are extended horizontally outward, the dumbbells are 0.99 m from the axis of rotation. There are 180 degrees of separation between the extended arms. The student rotates with an angularContinue reading “ROTATIONAL MOTION: Rotational Inertia”
CENTRIPETAL ACCELERATION
Q: What is the centripetal acceleration of a point located 7.50 cm from the central axis of an ultracentrifuge spinning at a rate of 7.5 x 104 rev/min? A: The given rate of 7.5 x 104 revolutions per minute is converted to radians per second ( ⍵ ) in the latter stages of the solutionContinue reading “CENTRIPETAL ACCELERATION”
RENAISSANCE PHYSICS 