Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
A grindstone of radius 4.0m is initially spinning with an angular speed of 8.0 rad/s . The angular speed is then increased to 10 rad/s over the next 4.0 seconds . Assume that the angular acceleration is constant . What is the average angular speed of the grindstone ?
Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
During the time a compact disc (cd) accelerates from rest to a constant rotational speed of 477 rev/min, it rotates through an angular displacement of 0.0250 rev . What is the angular acceleration of the CD ?
Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
During the spin-dry cycle of a washing machine , the motor slows from 95 rad/s to 30 rad/s while the turning the drum through an angle of 402 radians . What is the magnitude of the angular acceleration of the motor ?
Physics Rotational Mechanics Level: High School
Circular Motion
What is the angular speed in rad/s of the second hand of a watch ?
Physics Rotational Mechanics Level: High School
Circular Motion A bicycle travels 141 m along a circular track of radius 15 m . What is the angular displacement in radians of the bicycle from its starting position ?
Physics Rotational Mechanics Level: High School
Conservation of Angular Momentum
A flat uniform circular disk (radius = 2.40 m , mass = 1.00 102 kg) is initially stationary . The disk is free to rotate in the horizontal plane about a frictionless axis perpendicular to the center of the disk . A 55.0 kg person standing 1.15 m from the axis , begins to run on the disk in a circular path and has a tangential speed of 2.00 m/s relative to the ground . Find the resulting angular speed of the disk (in rad/s) and describes the direction of the rotation
Physics Rotational Mechanics Level: High School
Conservation of Angular Momentum
A woman stands at the center of a platform . The women and the platform rotate with an angular speed of 5.00 rad/s . Friction is negligible . Her arms are outstretched , and she is holding a dumbbell in each hand . In this position the total moment of inertia of the rotating system (platform women, and dumbbells) is 5.40 kgm2 . By pulling in her arms . she reduces the moment of inertia to 60 kgm2 . Find her new angular speed .
Physics Rotational Mechanics Level: High School
Conservation of Angular Momentum
A bowling ball encounters a 0.76 m vertical rise on the way back to the ball rack . Ignore frictional losses and assume that the mass of the ball is distributed uniformly. If the translational speed of the ball is 5.10 m/s at the bottom of the rise , find the translational speed at the top .
Physics Rotational Mechanics Level: High School
Conservation of Energy
A helicopter has two blades , each of which has a mass of 240 kg can be approximately as a thin rod of length R = 8.1 m .
Physics Rotational Mechanics Level: High School
Conservation of Energy
A thin uniform rod is initially positioned in the vertical direction , with its lower end attached to a frictionless axis that is mounted on the floor . The rod has a length of 2.50 m and is allowed to fall , starting from rest . Find the tangential speed of the free end of the rod , just before the rod hits the floor after rotating through 90 degrees .
Physics Rotational Mechanics Level: High School
Rotational Equilibriums
A women who weighs 4.80 102 N is leaning against a smooth vertical wall .a) Find the force FN (directed perpendicular to the wall) exerted on her shoulder by the wall .
b) Find the horizontal component of the force exerted on her shoes by the ground .
c) Find the vertical component of the force exerted on her shoes by the ground
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Physics Rotational Mechanics Level: High School
Equilibrium of moments
A uniform plank of length 4.6 m and weight 216 N rests horizontally on two supports , with 1.1 m of the plank hanging over the right support . To what distance x can a person who weighs 452 N walk on the overhanging part of the plank before it just begins to tip ?
Physics Rotational Mechanics Level: High School
In San Francisco a very simple technique is used to turn around a cable car when it reaches the end of its route . The car rolls onto a turntable , which can rotate about a vertical axis through its center . Then , two people push perpendicularly on the car , one at each end . The turntable is rotated one-half of a revolution to turn the car around . If the length of the car is 9.00 m and each person pushes with a 170 N force , what is the magnitude of the torque applied to the car ?
Physics Rotational Mechanics Level: High School
Circular Motion
Two people start at the same place and walk around a circular lake in opposite directions . One has and angular speed of 1.2 10-3 rad/s , while the other has an angular speed of 3.5 10-3 rad/s . How long will it be before they meet ?
Physics Rotational Mechanics Level: High School
Circular Motion
Suppose you are riding a stationary exercise bicycle , and the electronic meter indicates that the wheel is rotating at 8.2 rad/s . The wheel has a radius of 0.45m . If you ride the bike for 2070 s , how far would you have gone if he bike could move ?