A helicopter has a large main rotor that rotates in a horizontal plane and provides lift. There is also a small rotor on the tail that rotates in a vertical plane. What is the purpose of the tail rotor? (Hint: If there were no tail rotor, what would happen when the pilot changed the angular speed of the main rotor?) Some helicopters have no tail rotor, but instead have two large main rotors that rotate in a horizontal plane. Why is it important that the two main rotors rotate in opposite directions?
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
Introduction to Electrodynamics
Essential University Physics: Volume 2 (3rd Edition)
College Physics
Life in the Universe (4th Edition)
Essential University Physics (3rd Edition)
Essential University Physics: Volume 1 (3rd Edition)
- The puck in Figure 10.25 has a mass of 0.120 kg. The distance of the puck from the center of rotation is originally 40.0 cm, and the puck is sliding with a speed of 80.0 cm/s. The string is pulled downward 15.0 cm through the hole in the frictionless table. Determine the work done on the puck. (Suggestion: Consider the change of kinetic energy.)arrow_forwardYou have an internship working at a company that designs and produces washing and drying equipment. Your supervisor is in the process of designing a new, very large dryer to be used in commercial establishments with intense laundry needs, such as restaurants (tablecloths, napkins) and hotels (sheets, towels). In a dryer, a cylindrical tub containing wet material is rotated steadily about a horizontal axis as shown in the figure below. So that the material will dry uniformly, it is made to tumble. The rate of rotation of the smooth-walled tub is chosen so that a small piece of cloth will lose contact with the tub when the cloth is at an angle of e = 53.0° above the horizontal. Your supervisor's tub is designed to have a radius of r = 1.28 m and she asks you to determine the appropriate rate of revolution. (Give your answer in rev/min.) rev/minarrow_forwardSlip. Consider the figure below. If us = 1/(2+ V3) between the surfaces, what is the smallest possible 0 such that the block does NOT slip while resting on the circular surface? O 15° O 30° O 75° O 60°arrow_forward
- Vlad needs to draw water from a deep well. He is using a bucket that is connected by rope (negligible mass) to a wooden axle at the top of the well. By cranking a handle at the end of the axle, Vlad is able to unwind the rope around the axle and move the bucket downward. The radius of the axle is R = 30 cm. The bucket is traveling downward at speed vi = 25 cm/s when the handle slips out of Vlad’s hand. As the rope unwinds and the bucket falls downward, the axle spins freely with an angular acceleration whose magnitude is α = 4.5 rad/s^2. The bucket falls through a distance of d = 7.0 m before crashing into the water. 1. What is the angular speed ωf of the axle when the bucket first hits the water? 2. As d → 0, what limit does ωf approach and why?arrow_forwardA turntable with a mass of 12 kg and a radius of 1.8 meters spins at a constant angular velocity of 140 rpm. A 3-kg brick with a width of 15 cm and a depth of 30 cm falls onto the turntable, so the brick's center of mass is one meter away from the turntable's center. If there's no friction between the brick and turntable and they eventually spin at the same angular speed, what is their final angular speed, in rev/min or in rad/s? Justify your answer with your rationale and equations used. Moments of Inertia: Idisk = MR² for rotation about its center of mass parallel to the z-axis. Iblock = M (W² + D²) for rotation about its center of mass parallel to the z-axis.arrow_forwardA solid cylinder and a hollow cylinder have the same mass, same radius, and turn on frictionless, horizontal axles. (The hollow cylinder has lightweight spokes connecting it to the axle.) A rope is wrapped around each cylinder and tied to a block. The blocks have the same mass and are held the same height above the ground as shown. Both blocks are released simultaneously. The ropes do not slip. Which block hits the ground first? Or is it a tie? Explain.arrow_forward
- a bucket of water with a mass of 25 kilograms is lifted from a well by a rope which is wound around a cylinder with a radius of 0.10 meters. A 0.50 meter crank is attached to the cylinder so that it wraps the rope around the cylinder. what is the minimum force that must be applied to the crank to lift the water bucket ?arrow_forwardThe Cavendish balance shown in the figure below has two large lead balls, each of mass M = 1.5 kg, and two smaller lead balls, each of mass m = 0.8 kg. The lengths of the suspended rod to which the two smaller balls are attached and the fixed rod to which the larger balls are attached are both 40 cm as measured from the center of each lead ball. a) If the angle between the centers of the large and small balls is Δθ = 22 degrees with respect to the rotational axis established by the quartz fiber, find the force of gravitational attraction between each pair of large and small balls. b) What is the minimum angle, θ, between the centers of the large and small balls with respect to the quartz fiber?arrow_forwardA turntable with a mass of 12 kg and a radius of 1.8 meters spins at a constant angular velocity of 140 rpm. A 3-kg brick with a width of 15 cm and a depth of 30 cm falls onto the turntable, so the brick's center of mass is one meter away from the turntable's center. If there's no friction between the brick and turntable and they eventually spin at the same angular speed, what is their final angular speed, in rev/min or in rad/s? Justify your answer with your rationale and equations used. Moments of Inertia: I disk MR? for rotation about its center of mass parallel to the z-axis. = Iblock 5M (W2 + D² ) for rotation about its center of mass parallel to the z-axis.arrow_forward
- A sledge hammer has a 5 kg metal head located at the end of a 2 m long uniform shaft of mass 1 kg. The center of mass of the sledge hammer from its head is: 1.83 m 1.00 m O 0.167 m O 0.1 marrow_forwardThe diameters of the main rotor and tail rotor of a single-engine helicopter are 7.52 and 1.05 m, respectively. The respective rotational speeds are 452 rev/min and 4,120 rev/min. Calculate the speeds of the tips of both rotors. Main rotor____m/s Tail rotor____m/s Compare these speeds with the speed of sound, 343 m/s. V Main rotor=____v sound V tail rotor=____v soundarrow_forwardStars originate as large bodies of slowly rotating gas. Because of gravity, these clumps of gas slowly decrease in size. The angular velocity of a star increases as it shrinks because of answer choices conservation of angular momentum conservation of linear momentum conservation of energy the law of universal gravitation conservation of massarrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning