Exam 7: Rotational Motion

At time t = 0 s,a wheel has an angular displacement of zero radians and an angular velocity of +28 rad/s.The wheel has a constant acceleration of -0.51 rad/s².In this situation,the time t,at which the wheel comes to a mandatory halt,is closest to:

A 95 N force exerted at the end of a 0.50 m long torque wrench gives rise to a torque of 15 N · m.What is the angle (assumed to be less than 90°)between the wrench handle and the direction of the applied force?

A child is sitting on the outer edge of a merry-go-round that is 18 m in diameter.If the merry-go-round makes 4.9 rev/min,what is the velocity of the child in m/s?

A torque of 12 N ∙ m is applied to a solid,uniform disk of radius 0.50 m.If the disk accelerates at 5.7 rad/s²,what is the mass of the disk?

A machinist turns the power on to a grinding wheel,at rest,at time t = 0 s.The wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s.The wheel is run at that angular velocity for 40 s and then power is shut off.The wheel slows down uniformly at 1.5 rad/s² until the wheel stops.In this situation,the time interval of deceleration is closest to:

A small mass is placed on a record turntable that is rotating at 45 rpm.The linear acceleration of the mass is

A solid,uniform sphere of mass 2.0 kg and radius 1.7 m rolls without slipping down an inclined plane of height 7.0 m.What is the angular velocity of the sphere at the bottom of the inclined plane?

If you deform an object,you do not change its mass but you may change its moment of inertia and the location of its center of mass.

A particular motor can provide a maximum of 110.0 N · m of torque.Assuming that all of this torque is used to accelerate a solid,uniform flywheel of mass 10.0 kg and radius 3.00 m,how long will it take for the flywheel to accelerate from rest to 8.13 rad/s?

A force of 16.88 N is applied tangentially to a wheel of radius 0.340 m and gives rise to an angular acceleration of 1.20 rad/s².Calculate the rotational inertia of the wheel.

Through what angle in degrees does a 33 rpm record turn in 0.32 s?

A disk and a sphere are released simultaneously at the top of an inclined plane.They roll down without slipping.Which will reach the bottom first?

If a spinning object has a negative angular acceleration,it must be slowing down.

A wheel accelerates from rest to 59 rad/s at a rate of 74 rad/s².Through what angle (in radians)did the wheel turn while accelerating?

A force of 17 N is applied to the end of a 0.63 m long torque wrench at an angle 45° from a line joining the pivot point to the handle.What is the magnitude of the torque generated about the pivot point?

A bicycle heading west at 2.0 m/s turns 90.0° to the left in 10.0 s.The final velocity of the bicycle after the turn is 4.2 m/s to the south.Find the direction of the wheel's average angular acceleration.Express your answer as an angle relative to east.

-In the figure,a given force F is applied to a rod in several different ways.In which case is the torque due to F about the pivot P greatest?

At time t = 0 s,a wheel has an angular displacement of zero radians and an angular velocity of +14 rad/s.The wheel has a constant acceleration of -0.41 rad/s².In this situation,the time at which the angular displacement is + 88 rad and decreasing is closest to:

There must be equal amounts of mass on either side of the center of mass.

A cylinder and a sphere,both solid and uniform and having the same mass and diameter,roll without slipping down the same ramp starting from rest.Both of them will reach the ground at the same time.