Physics Rotational Mechanics Level: High School
Rotational equilibrium
A uniform plank of length 4.6 m and weight 225 N rests horizontally on two supports , with 1.1 m of the plank hanging over the right support ( see the figure at “click here”) . To what distance x can a person who weighs 460 N walk on the overhanging part of the plank before it just begins to tip ?
Physics Rotational Mechanics Level: High School
The drawing at “click here” shows a jet engine suspended beneath the wing of an airplane . The weight W of the engine is 9300 N and acts as shown in the drawing. In flight the engine produces a thrust T of 69200 N that is parallel to the ground . The rotational axis in the drawing is perpendicular to the plane of the paper . With respect to this axis , find the magnitude of the torque due to each of the following forces
Physics Rotational Mechanics Level: High School
Conservation of angular momentum
A person of mass 59.3 kg stands at the center of a rotating merry-go-round platform of radius 2.33 m and moment of inertia 666 kg.m^2 . The platform rotates without friction with an angular velocity of 2.16 rad/s . The person walks radially to the edge of the platform . Calculate the angular velocity when the person reaches the edge .(a) Calculate the rotational kinetic energies of the system of platform plus person before and after the person’s walk .
Physics Rotational Mechanics Level: High School
What is the angular moment of a figure skater spinning (with arms in close to her body) at 3.34 revolutions per second , assuming her to be a uniform cylinder with a height of 1.30 m , a radius of 15.9 cm , and a mass of 50.0 kg .(a) How much torque is required to slow her to a stop in 4.57s , assuming she does not move her arms ?
Physics Rotational Mechanics Level: High School
A bowling ball of mass 7.14 kg and radius 8.82 cm rolls without slipping down a lane at 5.48 m/s . Calculate its total kinetic energy .
Physics Rotational Mechanics Level: High School
Calculate the moment of inertia of the array of point objects shown in the figure at “click here” about the vertical axis . (Assume the objects are connected by very light rigid wires . Assume that m = 1.66 kg and M = 3.17 kg . The array is rectangular with L1 = 1.40 m , W = 0.571 m and L2 = 0.474 m . The array is rectangular and it is split through the middle by the horizontal axis)(a) Calculate the moment of inertia of the array of point objects about the horizontal axis .
Physics Rotational Mechanics Level: High School
A person exerts a force of 40.3 N on the end of a door 82.8 cm wide . What is the magnitude of the torque if the force is exerted perpendicular to the door ?a) What is the magnitude of the torque if the force is exerted at a 60.4 degrees angle to the face of the door ?
Physics Rotational Mechanics Level: High School
Equation of rotational motion
The tires of a car make 87.0 revolutions as the car reduces its speed uniformly from 88.7 km/hr to 57.5 km/hr . The tires have a diameter of 0.906 m . What was the angular acceleration ?If the car continues to decelerate at this rate , how much more time is required for it to stop ?
Physics Rotational Mechanics Level: High School
Equation of rotational motion
A 57.0 cm diameter wheel accelerates uniformly from 202 rpm to 370 rpm in 6.08 s. How far will a point on the edge of the wheel have traveled in this time ?
Physics Rotational Mechanics Level: High School
Equation of rotational motion
The blades in a blender rotates at a rate of 7730 rpm . When the motor is turned off during operation , the blades slow to rest in 3.21 s . What is the angular acceleration as the blades slow down ?
Physics Rotational Mechanics Level: High School
A 0.400 m diameter grinding wheel rotates at 1918 rpm . Calculate its angular velocity
Physics Ray Optics Level: High School
A convex mirror is used to reflect light from an object placed 60 cm in front of the mirror . The radius of the curvature is R = 88 cm .a) Find the location of the image .
b) Draw the ray diagram .
Physics Electrostatics Level: High School
A charge is placed on the x-axis (q = +10 micro Columbs , x = -0.6 m) , and another charge is placed on the y axis (q = +15 microColumbs , y = 0.8 m ) . A third charge (q = -6 microColumbs, m = 7 x 10^-8 kg) is placed at the coordinate origin . If the charge at the origin were free to move , what would be,a) the magnitude of its acceleration ?
b) the direction of its acceleration ?
Specify the answer as an angle relative to the –x axis .
Physics Electrostatics Level: High School
Two spherical shells have a common center . A +2 x 10^-6 C charge is spread uniformly over the inner shell , which has a radius of 0.1 m . A -5 x 10^-6 C charge is spread uniformly over the outer shell , which has a radius of 0.2 m . Find the magnitude and direction of the electric field at a distance (measured from the common center ) of :a) 0.05 m
b) 0.15 m
Physics Electromagnetic Waves Level: High School
The average intensity of sunlight reaching the earth is 1.390 W/m^2 with an electric field whose rms value is E = 720 N/C . A charge of 2.6 x 10^-8C is placed in the path of this electromagnetic wave .a) What is the magnitude of the electric force the charge experiences ?
b) If the charge is moving at a speed of 3.7 x 10^4 m/s , what is the magnitude of the magnetic force that the charge could experience ?
