Physics Rotational Mechanics Level: High School
Rotational Equilibrium
How far out on the diving board (see figure at “click here”) would a 56.6 kg diver have to be exert a torque of 1270 m*N on the board , relative to the left support post ?
Physics Rotational Mechanics Level: High School
Conservation of Angular Momentum
A solid spheres of radius R rotates about a diameter with an angular speed omega . The sphere then collapses under the action of internal forces to a final radius R/2 . What is the final angular speed of the sphere ?
Physics Rotational Mechanics Level: High School
Rotational Kinetic Energy
A 50-kg rider on a moped of mass 75 kg is traveling with a speed of 20 m/s . Each of the two wheels of the moped has a radius of 0.2 m and a moment of inertia of 0.2 kg*m^2 . What is the total rotational kinetic energy of the wheels ?
Physics Rotational Mechanics Level: High School
A string is wrapped around a pulley of radius 0.10 m and moment of inertia 0.15 kg*m^2 . The string is pulled with a force of 12 N . What is the magnitude of the resulting angular acceleration of the pulley ?
Physics Rotational Mechanics Level: High School
Moment of Inertia
Two uniform solid spheres , A and B have the same mass . The radius of sphere B is twice that of sphere A . The axis of rotation passes through each sphere . Which one of the following statements concerning the moments of inertial are true ?a) The moment of inertia of A is ¼ that of B .
b) The moment of inertia of A is ½ that of B .
c) The moment of inertia of A is 5/4 that of B .
d) The moment of inertia of A is 5/8 that of B .
e) The two spheres have equal moments of inertia .
Physics Rotational Mechanics Level: High School
Centre of Gravity
Consider four point masses located as shown in the sketch at “click here” . The acceleration due to gravity is the same everywhere . What is the x coordinate of the center of gravity for this system ?
Physics Rotational Mechanics Level: High School
Rotational Equilibrium
An 80-kg man balances the boy on a teeter-totter as shown in the figure at “click here” . What, approximately , is the magnitude of the downward force exerted on the fulcrum ?
Physics Rotational Mechanics Level: High School
A 12-N force is applied 7.0 cm from the axis of rotation . What is the torque due to the applied force ?
Physics Rotational Mechanics Level: High School
A circular hoop rolls without slipping on a flat horizontal surface . Which one of the following is necessarily true ?a) All point on the rim of the hoop have the same speed .
b) All points on the rim of the hoop have the same velocity .
c) Every point on the rim of the wheel has a different velocity .
d) All points on the rim of the hoop have acceleration vectors that are tangent to the hoop .
e) All points on the rim of the hoop
Physics Rotational Mechanics Level: High School
A rigid body rotates about a fixed axis with a constant angular acceleration . Which one of the following statements is true concerning the tangential acceleration of any point on the body ?a) Its magnitude is zero m/s^2 .
b) It depends on the angular velocity .
c) It is equal to the centripetal acceleration
d) It is constant in both magnitude and direction .
e) It depends on the change in the angular velocity .
Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
What is the tangential speed of a lug nut on the wheel of a car if the lug nut is located 0.114 m from the axis of rotation and the wheel is rotating at 6.53 rev/sec ?
Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
A roulette wheel with a 1.0-m radius reaches a maximum angular speed of 18 rad/s before it stops 35 revolutions (220 rad) after attaining top speed . How long did it take the wheel to stop ?
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 ?