Physics Rotational Mechanics Level: High School
A disk with a moment of inertia I = 0.5 kg-m^2 is rotating about the center of mass with an angular velocity of omega = 2 radians/sec . It is decelerated at a rate of 0.5 radians/s2 . What is the applied constant torque ?a. 0.750 N-m
b. 0.250 N-m
c. 1.00 N-m
d. 0.500 N-m
e. 4.00 N-m
Physics Rotational Mechanics Level: High School
A rigid body is free to translate and rotate . It is in accelerated motion and it is rotating about its center of mass at a constant angular velocity , Therefore ,a. the sum of all external forces is zero .
b. the body is in static equilibrium .
c. the body’s kinetic energy is constant .
d. All of the above .
e. The sum of all external forces is zero .
Physics Rotational Mechanics Level: High School
The position of a pendulum is described by è(t) = 0.04 Cos (t + pi / 2)z. The angular frequency of the pendulum is :a. pi/2 radians/sec
b. 1 radian/sec
c. 2 pi radians/sec
d. 2 pi t radians/sec
c. è/22 pi radians/sec
Physics Rotational Mechanics Level: High School
Rocket thrust can be explained by:a. Conservation of energy.
b. Conservation of forces.
c. Conservation of angular momentum
d. Conservation of linear momentum
e. Conservation of mass.
f. None of the above.
Physics Rotational Mechanics Level: High School
The angular momentum of the planets orbiting about the Sun is conserved because:a. L= constant.
b. T = 0
c. Sigma r.F = 0
d. The gravitational force between the Sun and the planet is a central force.
e. All of the above.
f. Only a and c are true.
Physics Rotational Mechanics Level: High School
A torque of 100 kg-m^2/s^2 is applied to a flywheel with I = 10 kg-m^2. The rate of change of the angular momentum of the flywheel is :a. 100 kg-m^2/s^2
b. 10^3 kg-m^2/s^2
c. 10 kg-s^2/S^2
d. 10^-2 s^2/kg-m^2
e. 10^4 kg^2-m^4/s^4
Physics Rotational Mechanics Level: High School
If all the passengers on a shipping , frictionless , non-powered merry-go-round should suddenly move from edge towards the center.a. There would be no noticeable effect.
b. The angular velocity would increase.
c. The angular velocity would decrease.
d. The angular momentum would be altered.
e. Both b and d are correct.
Physics Rotational Mechanics Level: High School
A sphere rolling down a plane :a. Has translational kinetic energy.
b. Has rotational kinetic energy.
c. Has the potential to do work.
d. All of the above.
e. Only a and b above.
Physics Rotational Mechanics Level: High School
Under which of the following condition is BOTH the angular momentum and the linear momentum of a rigid body conserved ?a. The sum of the external forces equals zero .
b. The sum of the external torques equals zero .
c. The system is isolated .
d. All external forces are conservative .
e. The sum of internal forces equals zero .
Physics Rotational Mechanics Level: High School
Centre of Mass
Find the center of mass of this two-body system. (Notice the notation for subscripts , eg , msub 1 = letter m with a sub 1 notation.)msub 1 = 2-kg .
rsub 1 = (2,6)
msub 2 = 3-kg
rsub 2 = (2,-4)
a. (2,24)
b. (0,26)
c. (24,0)
d. (2,0)
e. (10,0)
f. None of the above .
Physics Rotational Mechanics Level: High School
A sphere rolling down a plane :a. Has translational kinetic energy .
b. Has rotational kinetic energy .
c. Has the potential to do work .
d. All of the above .
e. Only a and b above .
Physics Rotational Mechanics Level: High School
A uniform bar of length 28 m and mass 8kg is attached to a wall with a hinge that exerts on the bar the horizontal force Hx and a vertical force Hy . The bar is held by a cord that makes a 90 degree angle with respect to bar and angle 31degree with respect to wall . The acceleration of gravity g = 9.8 m/s^2 . What is the magnitude of the horizontal force Hx on the pivot ? Answer in units of N .
Physics Rotational Mechanics Level: High School
Calculate the change in kinetic energy of the system . Answer in units of J .
Physics Rotational Mechanics Level: High School
A student sits on a rotating stool holding two 4 kg objects . When his arms are extended horizontally , the objects are 1.1 m from the axis of rotation , and he rotates with angular speed of 0.65 rad/sec . The moment of inertia of the student plus the stool is 4kg m^2 and is assumed to be constant . The student then pulls the objects horizontally to a radius 0.38 m from the rotation axis .Calculate the final angular speed of the student . Answer in units of rad/s .
Physics Rotational Mechanics Level: High School
Calculate the gravitational acceleration of each of three planets with the masses in kilograms and the radii in meters . The units of gravitational acceleration would turn out to be meters per squared seconds . Use the expression GM/r squared and show the work .Planet 1 Mercury : 3,30E + 23 (kg) 2439 (km) radii
Planet 2 Venus : 4,87E + 27 (kg) 6051 (km) radii
Planet 3 Mars : 6.42E + 23(kg) 3396 (km) radii
