Physics Rotational Mechanics Level: High School
A woman who weighs 4.92 x 10^2 N is leaning against a smooth vertical wall , as the drawing shows at “click here” .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 .
Physics Rotational Mechanics Level: High School
By means of a rope whose is mass is negligible , two blocks are suspended over a pulley , as the drawing at “click here” shows, with m1 = 11.7 kg and m2 = 45.3 kg . The pulley can be treated as a uniform, solid , cylindrical disk . The downward acceleration of the 45.3 kg block to be exactly one-half the acceleration due to gravity . Noting that the tension in the rope is not the same on each side of the pulley, find the mass of the pulley .
Physics Rotational Mechanics Level: High School
A solid circular disk has a mass of 1.2 kg and a radius of 0.17 m . Each of three identical thin rods has a mass of 0.16 kg . The rods are attached perpendicularly to the plane of the disk at its outer edge to form a three-legged stool . (see the drawing at “click here”) . Find the moment of inertia of the stool with respect to an axis that is perpendicular to the plane of the disk at its center . (Hint: When considering the moment of inertia of each rod , note that all of the mass of each rod is located at the same perpendicular distance from the axis .)
Physics Rotational Mechanics Level: High School
A solid circular disk has a mass of 1.2 kg and a radius of 0.17 m . Each of three identical thin rods has a mass of 0.16 kg . The rods are attached perpendicularly to the plane of the disk at its outer edge to form a three-legged stool . (see the drawing at “click here”) . Find the moment of inertia of the stool with respect to an axis that is perpendicular to the plane of the disk at its center . (Hint: When considering the moment of inertia of each rod , note that all of the mass of each rod is located at the same perpendicular distance from the axis .)
Physics Rotational Mechanics Level: High School
A rotational axis is directed perpendicular to the plane of a square and is located as shown in the drawing figure at “click here” . Two forces F1 and F2 , are applied to diagonally opposite corners , and act along the sides of the square , first shown in part a and then part b of the drawing . In each case the net torque produced by the forces is zero . The square is one meter on a side ,and the magnitude of F2 is 2 times that of F1 , find the distance a and b that locate the axis . Note that a and b are drawn to scale .
Physics Rotational Mechanics Level: High School
The crane shown in the drawing at “click here” is lifting a 180 kg crate upward with an acceleration of 1.5 m/s^2 . The cable from the crate passes over a solid cylindrical pulley at the top of the boom . The pulley has a mass of 130 kg . The cable is then wound onto a hollow cylindrical drum that is mounted on the deck of the crane . The mass of the drum is 150 kg, and its radius is 0.76 m . The engine applies a counterclockwise torque to the drum in order to wind up the cable . What is the magnitude of this torque ? Ignore the mass of the cable .
Physics Rotational Mechanics Level: High School
Centre of Mass
The coordinates of three particles are (5,7) (0,3) and (-1, -1). If the three particles have 1.0 kg , 2.0 kg and 2.0 kg respectively , find the coordinates of the center of mass .
Physics Rotational Mechanics Level: High School
Circular Motion
A car traveling on a flat (unbanked) circular track acceleration uniformly from rest with a tangential acceleration of 1.70 m/s^2 . the car makes it one quarter of the way around the circle before it skids off the track . Determine the coefficient of static friction between the car track from these data .
Physics Rotational Mechanics Level: High School
Rotational Kinematics
A merry go round is stationary . A dog is running on the ground just outside its circumference , moving with a constant angular speed of 0.750 rad/s . the dog does not change his pace when he sees what he has been looking ; a bone resting on the edge of the merry go round one third of a revolution in front of him . At the instant the dog sees the bone (t = 0) , the merry go round begins to move in the direction the dog is turning , with a constant angular acceleration of 0.0150 rad/s^2 .a) at what time will the dog reach the bone ?
b) the confused dog keeps running and passes the bone . How long after the merry go round starts to turn do the dog and the bone draw even with each other for the second time ?
Physics Rotational Mechanics Level: High School
Rotational Kinematics
During a certain period of time , the angular position of a swinging door is described by theta = 5.00 + 10.0 t + 2.00 t^2 , where theta is in radians and t is in seconds . Determine the angle (in radians ) through which the drill rotates during this period .
Physics Rotational Mechanics Level: High School
Centre of Mass
In the ammonia (NH3) molecule , three hydrogen atoms form an equilateral triangle , with the center of the triangle at distance d = 9.40 x 10^-11 m from each hydrogen atom . Nitrogen atom is at the apex of a pyramid , with the three hydrogen atoms forming the base . The nitrogen to hydrogen atomic mass ratio is 13.9 , and the nitrogen to hydrogen distance is L = 10.14 x 10^-11 m . What are the x and y coordinates of the molecule’s center of mass ?
Physics Rotational Mechanics Level: High School
Rotational Equilibrium
The automatic flag raising system on a horizontal flagpole attached to the vertical outside wall of a tall building has become stuck . The management of the building wants to send a person crawling out along the flagpole to fix the problem . Because of your physics knowledge, you have been asked to consult with a group to decide whether or not this is possible . You are all to aware that no one could survive the 250 foot fall from the flagpole to the ground . The flagpole is a 120 lb steel I-beam which is very strong and rigid . One side of the flagpole is attached to the wall of the building by hinge so that it can rotate vertically . Nine feet away , the other end of the flagpole is attached to a strong , lightweight cable . The cable goes up from the flagpole at an angle of 30 degree unit it reaches the building where it is bolted to the wall . The mechanic who will climb out on the flagpole weighs 150 lbs including equipment . From the specification of the building construction , both the bolt attached the cable to the building and the hinge have been tested to hold a force of 500 lbs . Your boss has decided that the worse case is when the mechanic is at the far end of the flagpole , nine feet from the building .
Physics Rotational Mechanics Level: High School
Pulley with rotational Inertia
The two blocks in the figure which is shown at “click here” are connected by a massless rope that passes over a pulley . The pulley is 12 cm in diameter and has a mass of 2.0 kg . As the pulley turns, friction at the axle exerts a torque of magnitude 0.50 Nm . If the blocks are released from rest , how long does it take the 4.0 kg block to reach the floor ?
Physics Rotational Mechanics Level: High School
Torque
The 200 g model rocket shown in the figure generates 4.0 N of thrust .It spins in a horizontal circle at the end of a 100 g rigid rod . What is its angular acceleration ?
Physics Rotational Mechanics Level: High School
Rotaional Kinematics
A uniform solid cylinder which is shown at “click here” has a radius of 0.35 m and a mass of 25 kg . If these force were applied for 6.5 seconds find the angular velocity and angle that the cylinder has rotated through .