Physics Rotational Mechanics Level: Misc Level
A 200 g object is moving in a circle of radius 4 m with a uniform speed of 6 m/s. The net force acting on the object is:
Physics Rotational Mechanics Level: Misc Level
Three masses are positioned at the following coordinates :3.0 kg at ( 3,2) : 4.0 kg at (0,1) :and 5.0 kg at ( 5,-7). what are the coordinates of the center of mass of this system?
Physics Rotational Mechanics Level: Misc Level
The positions of three particles, written as ( x, y ) coordinates, are: particle 1 ( mass 4.3 kg ) at ( 3.5 m, 0 m ): particle 2 ( mass 5,7 kg ) at ( 2.1 m, 4.5 m,): particle 3 ( mass 3.4 kg ) at ( -1.1 m, -1.9 m). What is the location of the center of mass?
x cm= m
y cm =m
Physics Rotational Mechanics Level: Misc Level
A 60.0- kg man stands at one end of a 20.0- kg uniform 10.0 -m long board. How far from the man is the center of mass of the man - board system?
a. 1.25 m
b. 2.50 m
c. 5.00 m
d. 7.50 m
Physics Rotational Mechanics Level: Misc Level
In an Atwood s machine : M 1 =20 kg, M 2 =30 kg, and a pulley has a radius of 20 cm and a moment of inertia of 0.500 kg m 2. Find the acceleration of M 2.
Physics Rotational Mechanics Level: Misc Level
A record table turn table is rotating at 45 R P M. The moment of inertia of the table is 0.002 kg m2. A record is dropped onto the turntable. If the record is initially at rest and has a moment of inertia of 0.0005 kg m2:
A) How fast are the two going immediately after the collision.( before the belt can act on the turntable)?
B) How much kinetic energy was lost during the collision?
Physics Rotational Mechanics Level: Misc Level
A uniforn 800 kg beam, 6 m long, is freely pivoted at P. The beam is supported in a horizontal position by a light strut, 5 m long, which is freely pivoted at Q and is loosely pinned to the beam at R. A load of mass is suspended from the end of the beam at S. A maximum compression of 22,000 N in the strut is permitted, due to safety. In Figure 11.1, the maximum mass M of the load is closest to:
A) 498 kg B) 1298 kg C) 722 kg D) 273 kg E) 1522kg
Physics Rotational Mechanics Level: Misc Level
A uniform disk has a mass of 3.7 kg and a radius of 0. 38 m. The disk is mounted on frictionless bearings and is used as a turntable. The turntable is initially rotating at 20 rpm. A thin -walled hollow cylinder has the same mass and radius as the disk. It is released from rest, just above the turntable, and on the same vertical axis. The hollow cylinder slips on the turntable for 0.20 s until it acquires the same final angular velocity as the turntable. The final angular momentum of the system is closest to:
A) 1.34 kg. m2 /s B) 1.12 kg. m2/s C) 1.68 kg. m2/s D) 0.80 kg. m2 /sE) 0.56 kg. m2/s
Physics Rotational Mechanics Level: Misc Level
A light triangular plate O A B is in a horizontal plane. Three forces, F1=3 N F2 =4 N, and F3 =8 N, act on the plate, which is pivoted about a vertical axes through point O. In Figure 10. 1, the moment arm of F1 about the axis through point O is closest to :
A) 0.90 N.m B) 1.6 N.m C) 1.8 N.m D) 1.1 N.m E) 1.4 N.m
Physics Rotational Mechanics Level: Misc Level
A machinist turns the power on to grinding wheel, at rest, at time t =0 s. The wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 80 rad/s.The wheel is run at that angular velocity for 20 s and then power is shut off.The wheel decelerates uniformly at 1.3 rad/s2 until the wheel stops. In this situation, the angular acceleration of the wheel between t =0 s and t= 10 s is closest to :
A) 8.0 rad/s2 B) 14 rad/s2 C) 13 rad/s2 D) 9.6 rad/s2 E) 11 rad/s2
Physics Rotational Mechanics Level: Misc Level
At time t= 0 s, a wheel has an angular displacement of zero radians and an angular velocity of +31 rad/s. The wheel has a constant acceleration of -0.55 rad /s2. In this situation, the time t, at which the wheel comes to a mandatory halt, is closest to:
A) 56 s B) 37 s C) 65) s D) 47 s E) 28 s
Physics Rotational Mechanics Level: Misc Level
Assume that the spool is a solid cylinder of radius 0.1 m and mass 5.0 kg, and m =1.0 kg
Find the angular speed of the spool after the mass m has fallen 1.0 m.
Physics Rotational Mechanics Level: Misc Level
A student sits on a rotating stool holding two 3.0 kg masses. When his arms extended horizontally, the masses are 1.0 m from the axis of rotation, and he rotates with an angular speed of 0.75 rad/s, the moment of inertia of the student plus stool is 3.0 kg m 2, and is assumed to be constant. The student then pulls the masses horizontally to 0.20 m from the rotation axis.
Find the new angular speed of the student.
Physics Rotational Mechanics Level: Misc Level
A cable passes over a pulley. Because of friction, the tension in the cable is not the same on opposite side of the pulley. The force in one side is 110 N, and the force on the other side is 100 N. Assume that the pulley is a uniform disk of mass 2.0 kg and radius 0.5 m.
Determine its angular acceleration.
Physics Rotational Mechanics Level: Misc Level
An electric motor rotating a workshop grinding wheel at a rate of 50 rev/min is switched off. Assume constant deceleration of 1.0 rad /s2
How long does it take for the grinding wheel to stop?
