A 68-kg commuter rides on an 8.1 -kg bicycle. Each bicycle wheel is a hoop of radius 33 cm and mass 1 A kg. (a) What energy must the biker supply to move at 7.2 m/s? include the kinetic energy of the biker, the kinetic energy of the bike frame, and the kinetic energy of the rotating wheels. (b) What percentage of the energy she expends goes into the rotation of the wheels? (c) What percentage goes into her own kinetic energy?
Trending nowThis is a popular solution!
Chapter 10 Solutions
EBK PHYSICS
Additional Science Textbook Solutions
Chemistry: A Molecular Approach (4th Edition)
Microbiology: An Introduction
Chemistry: Structure and Properties (2nd Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Cosmic Perspective Fundamentals
Human Biology: Concepts and Current Issues (8th 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_forwardThe puck in Figure P11.46 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.) Figure P11.46arrow_forwardTo develop muscle tone, a woman lifts a 2.00-kg weight held in her hand. She uses her biceps muscle to flex the lower arm through an angle of 60.0°. (a) What is the angular acceleration if the weight is 24.0 cm from the elbow joint, her forearm has a moment of inertia of 0.250kg-m2 and the net force she exerts is 750 N at an effective perpendicular lever arm of 2.00 cm? (b) How much work does she do?arrow_forward
- A small particle of mass m is pulled to the top of a friction less half-cylinder (of radius R) by a light cord that passes over the top of the cylinder as illustrated in Figure P7.15. (a) Assuming the particle moves at a constant speed, show that F = mg cos . Note: If the particle moves at constant speed, the component of its acceleration tangent to the cylinder must be zero at all times. (b) By directly integrating W=Fdr, find the work done in moving the particle at constant speed from the bottom to the top of the hall-cylinder. Figure P7.15arrow_forwardA space probe is fired as a projectile from the Earths surface with an initial speed of 2.00 104 m/s. What will its speed be when it is very far from the Earth? Ignore atmospheric friction and the rotation of the Earth. P11.26 Ki+Ui=Kf+Uf12mvi2+GMEm(1rf1ri)=12mvf212vi2+GME(01RE)=12vf2orvf2=v122GMEREandvf=(v122GMERE)1/2,vf=[(2.00104)21.25108]1/2m/s=1.66104m/sarrow_forwardA tennis ball is a hollow sphere with a thin wall. It is set rolling without slipping at 4.03 m/s on a horizontal section of a track as shown in Figure P10.62. It rolls around the inside of a vertical circular loop of radius r = 45.0 cm. As the ball nears the bottom of the loop, the shape of the track deviates from a perfect circle so that the ball leaves the track at a point h = 20.0 cm below the horizontal section. (a) Find the balls speed at the top of the loop. (b) Demonstrate that the ball will not fall from the track at the top of the loop. (c) Find the balls speed as it leaves the track at the bottom. What If? (d) Suppose that static friction between ball and track were negligible so that the ball slid instead of rolling. Would its speed then be higher, lower, or the same at the top of the loop? (e) Explain your answer to part (d). Figure P10.62arrow_forward
- Sophia is playing with a set of wooden toys, rolling them offthe table and onto the floor. One of the toys is a small spherewith a mass of 0.024 kg and a radius of 0.020 m, and another isa small cylinder that also has a mass of 0.024 kg but a radius of0.013 m. She rolls each toy so that it has the same translationalspeed of 0.40 m/s. How much greater is the kinetic energy ofthe cylinder than the kinetic energy of the sphere?arrow_forwardConsider two objects with m1 m2 connected by a light string that passes over a pulley having a moment of inertia of I about its axis of rotation as shown in Figure P10.44. The string does not slip on the pulley or stretch. The pulley turns without friction. The two objects are released from rest separated by a vertical distance 2h. (a) Use the principle of conservation of energy to find the translational speeds of the objects as they pass each other. (b) Find the angular speed of the pulley at this time.arrow_forwardA bowling ball of mass 7.00 kg is rolling at 3.00 m/s along a level surface. Calculate (a) the balls translational kinetic energy, (b) the balls rotational kinetic energy, and (c.) the balls total kinetic energy, (d) How much work would have to be done on the ball to bring it to rest? (See Section 8.6.)arrow_forward
- A small block of mass m = 200 g is released from rest at point along the horizontal diameter on the inside of a frictionless, hemispherical bowl of radius R = 30.0 cm (Fig. P7.45). Calculate (a) the gravitational potential energy of the block-Earth system when the block is at point relative to point . (b) the kinetic energy of the block at point , (c) its speed at point , and (d) its kinetic energy and the potential energy when the block is at point . Figure P7.45 Problems 45 and 46.arrow_forwardThe figure shows a rigid assembly of a thin hoop (of mass m = 0.24 kg and radius R = 0.16 m) and a thin radial rod (of length L = 2R and also of mass m = 0.24 kg). The assembly is upright, but we nudge it so that it rotates around a horizontal axis in the plane of the rod and hoop, through the lower end of the rod. Assuming that the energy given to the assembly the nudge is negligible, what is the assembly's angular speed about the rotation axis when it passes through the upside-down (inverted) orientation? Number i Rod Hoop ! Rotation axis Unitsarrow_forwardThe puck in the figure below has a mass of 0.120 kg. The distance of the puck from the center of rotation is originally 32.0 cm, and the puck is sliding with a speed of 80.0 cm/s. The string is pulled downward 12.5 cm through the hole in the frictionless table. Determine the work done on the puck. (Suggestion: Consider the change of kinetic energy.) J 1x 0 R marrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics 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 LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College