Principles of Physics: A Calculus-Based Text
5th Edition
ISBN: 9781133104261
Author: Raymond A. Serway, John W. Jewett
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 4, Problem 5CQ
If you hold a horizontal metal bar several centimeters above the ground and move it through grass, each leaf of grass bends out of the way. If you increase the speed of the bar, each leaf of grass will bend more quickly. How then does a rotary power lawn mower manage to cut grass? How can it exert enough force on a leaf of grass to shear it off?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Pete Zaria works on weekends at Barnaby's Pizza Parlor. His primary responsibility is to
fill drink orders for customers. He fills a pitcher full of Cola, places it on the counter top
and gives the 2.6-kg pitcher a 7.8 N forward push over a distance of 36 cm (0.36 m) to
send it to a customer at the end of the counter. The coefficient of friction between the
pitcher and the counter top is 0.25.
a. Determine the work done by Pete on the pitcher during the 36 cm push.
b. Determine the work done by friction upon the pitcher.
c. Determine the total work done upon the pitcher.
d. Determine the kinetic energy of the pitcher when Pete is done pushing it.
e. Determine the speed of the pitcher when Pete is done pushing it.
A 20 kg dog stands on a 40 kg platform that is supported by two ropes. One rope is attached to the right edge of the platform and the other is attached 50 cm from the left edge of the platform. The dog sits 50 cm from the right edge of the platform. A 5.0 kg cat jumps up, but is wary of the dog abs stays all the way on the left edge. The platform is 2.0 m long. What is the tension in each rope?
What is the x-component
y
X
40°
of this force?
10 N
A. 10 sin 40°
B. 10 cos 40°
C. -10 cos 40°
D. 10/sin 40°
Chapter 4 Solutions
Principles of Physics: A Calculus-Based Text
Ch. 4.1 - Which of the following statements is most correct?...Ch. 4.4 - An object experiences no acceleration. Which of...Ch. 4.4 - You push an object, initially at rest, across a...Ch. 4.5 - Prob. 4.4QQCh. 4.6 - (i) If a fly collides with the windshield of a...Ch. 4.6 - Which of the following is the reaction force to...Ch. 4.7 - Consider the two situations shown in Figure 4.8,...Ch. 4 - Prob. 1OQCh. 4 - Prob. 2OQCh. 4 - Prob. 3OQ
Ch. 4 - Prob. 4OQCh. 4 - Prob. 5OQCh. 4 - Prob. 6OQCh. 4 - Prob. 1CQCh. 4 - If a car is traveling due westward with a constant...Ch. 4 - A person holds a ball in her hand. (a) Identify...Ch. 4 - Prob. 4CQCh. 4 - If you hold a horizontal metal bar several...Ch. 4 - Prob. 6CQCh. 4 - Prob. 7CQCh. 4 - Prob. 8CQCh. 4 - Balancing carefully, three boys inch out onto a...Ch. 4 - Prob. 10CQCh. 4 - Prob. 11CQCh. 4 - Prob. 12CQCh. 4 - Prob. 13CQCh. 4 - Give reasons for the answers to each of the...Ch. 4 - Prob. 15CQCh. 4 - In Figure CQ4.16, the light, taut, unstretchable...Ch. 4 - Prob. 17CQCh. 4 - Prob. 18CQCh. 4 - Prob. 19CQCh. 4 - A force F applied to an object of mass m1 produces...Ch. 4 - (a) A car with a mass of 850 kg is moving to the...Ch. 4 - A toy rocket engine is securely fastened to a...Ch. 4 - Two forces, F1=(6i4j)N and F2=(3i+7j)N, act on a...Ch. 4 - Prob. 5PCh. 4 - Prob. 6PCh. 4 - Two forces F1 and F2 act on a 5.00-kg object....Ch. 4 - A 3.00-kg object is moving in a plane, with its x...Ch. 4 - A woman weighs 120 lb. Determine (a) her weight in...Ch. 4 - Prob. 10PCh. 4 - Prob. 11PCh. 4 - Prob. 12PCh. 4 - Prob. 13PCh. 4 - Prob. 14PCh. 4 - Prob. 15PCh. 4 - You stand on the seat of a chair and then hop off....Ch. 4 - Prob. 17PCh. 4 - A block slides down a frictionless plane having an...Ch. 4 - Prob. 19PCh. 4 - A setup similar to the one shown in Figure P4.20...Ch. 4 - Prob. 21PCh. 4 - The systems shown in Figure P4.22 are in...Ch. 4 - A bag of cement weighing 325 N hangs in...Ch. 4 - Prob. 24PCh. 4 - In Example 4.6, we investigated the apparent...Ch. 4 - Figure P4.26 shows loads hanging from the ceiling...Ch. 4 - Prob. 27PCh. 4 - An object of mass m1 = 5.00 kg placed on a...Ch. 4 - An object of mass m = 1.00 kg is observed to have...Ch. 4 - Two objects are connected by a light string that...Ch. 4 - Prob. 31PCh. 4 - A car is stuck in the mud. A tow truck pulls on...Ch. 4 - Two blocks, each of mass m = 3.50 kg, are hung...Ch. 4 - Two blocks, each of mass m, are hung from the...Ch. 4 - In Figure P4.35, the man and the platform together...Ch. 4 - Two objects with masses of 3.00 kg and 5.00 kg are...Ch. 4 - A frictionless plane is 10.0 m long and inclined...Ch. 4 - Prob. 39PCh. 4 - An object of mass m1 hangs from a string that...Ch. 4 - A young woman buys an inexpensive used car for...Ch. 4 - A 1 000-kg car is pulling a 300-kg trailer....Ch. 4 - An object of mass M is held in place by an applied...Ch. 4 - Prob. 44PCh. 4 - An inventive child named Nick wants to reach an...Ch. 4 - In the situation described in Problem 45 and...Ch. 4 - Two blocks of mass 3.50 kg and 8.00 kg are...Ch. 4 - Prob. 48PCh. 4 - In Example 4.5, we pushed on two blocks on a...Ch. 4 - Prob. 50PCh. 4 - Prob. 51PCh. 4 - Prob. 52PCh. 4 - Review. A block of mass m = 2.00 kg is released...Ch. 4 - A student is asked to measure the acceleration of...Ch. 4 - Prob. 55PCh. 4 - Prob. 56PCh. 4 - A car accelerates down a hill (Fig. P4.57), going...Ch. 4 - Prob. 58PCh. 4 - In Figure P4.53, the incline has mass M and is...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Why is the following situation impossible? A softball pitcher has a strange technique: she begins with her hand at rest at the highest point she can reach and then quickly rotates her arm backward so that the ball moves through a half-circle path. She releases the ball when her hand reaches the bottom of the path. The pitcher maintains a component of force on the 0.180-kg ball of constant magnitude 12.0 N in the direction of motion around the complete path. As the ball arrives at the bottom of the path, it leaves her hand with a speed of 25.0 m/s.arrow_forwardIf you hold a horizontal metal bar several centimeters above the ground and move it through grass, each leaf of grass bends out of the way. If you increase the speed of the bar, each leaf of grass will bend more quickly. How then does a rotary power lawn mower manage to cut grass? How can it exert enough force on a leaf of grass to shear it off?arrow_forwardWhy is the following situation impossible? A mischievous child goes to an amusement park with his family. On one ride, after a severe scolding from his mother, he slips out of his seat and climbs to the top of the rides structure, which is shaped like a cone with its axis vertical and its sloped sides making an angle of = 20.0 with the horizontal as shown in Figure P6.32. This part of the structure rotates about the vertical central axis when the ride operates. The child sits on the sloped surface at a point d = 5.32 m down the sloped side from the center of the cone and pouts. The coefficient of static friction between the boy and the cone is 0.700. The ride operator does not notice that the child has slipped away from his seat and so continues to operate the ride. As a result, the sitting, pouting boy rotates in a circular path at a speed of 3.75 m/s. Figure P6.32arrow_forward
- BIO When a gymnast performing on the rings executes the iron cross, he maintains the position at rest shown in Figure P10.85a. In this maneuver, the gymnasts feet (not shown) are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi (lats) and the pectoralis major (pecs). One of the rings exerts an upward fore Fh on a hand as shown in Figure P10.85b. The force Fs is exerted by the shoulder joint on the arm. The latissimus dorsi and pectoralis major muscles exert a total force Fm on the arm. (a) Using the information in the figure, find the magnitude of the force Fm. (b) Suppose an athlete in training cannot perform the iron cross but can hold a position similar to the figure in which the arms make a 45 angle with the horizontal rather than being horizontal. Why is this position easier for the athlete? Figure P10.85arrow_forwardA 0.400-kg pendulum bob passes through the lowest part of its path at a speed of 3.00 m/s. (a) What is the tension in the pendulum cable at this point if the pendulum is 80.0 cm long? (b) When the pendulum reaches its highest point, what angle does the cable make with the vertical? (c) What is the tension in the pendulum cable when the pendulum reaches its highest point?arrow_forwardA makeshift sign hangs by a wire that is extended over an ideal pulley and is wrapped around a large potted plant on the roof as shown in Figure P6.10. When first set up by the shopkeeper on a sunny and dry day, the sign and the pot are in equilibrium. Is it possible that the sign falls to the ground during a rainstorm while still remaining connected to the pot? What would have to be true for that to be possible? FIGURE P6.10 Problems 10 and 11.arrow_forward
- BIO The arm in Figure P10.35 weighs 41.5 N. The gravitational force on the arm acts through point A. Determine the magnitudes of the tension force F1 in the deltoid muscle and the force Fs exerted by the shoulder on the humerus (upper-arm bone) to hold the arm in the position shown. Figure P10.35arrow_forwardTo give a pet hamster exercise, some people put the hamster in a ventilated ball andallow it roam around the house(Fig. P13.66). When a hamsteris in such a ball, it can cross atypical room in a few minutes.Estimate the total kinetic energyin the ball-hamster system. FIGURE P13.66 Problems 66 and 67arrow_forwardAfrican elephants are the largest land animals. They consume approximately 10% of their body weight in food each day, which for an adult male, can be 1000 lb. of vegetation! Their diet consists mostly of grasses, bamboo, tree bark, and fruit. They also like to dine on tree leaves. To reach them, they often stand up on their hind legs and extend their trunks (see the figure). The elephant in the figure is in equilibrium. The location of the elephant's center of mass is shown, and the axis of rotation has been chosen to correspond to the hip joint. The forces in the elephant's free-body diagram are shown, and there is a static friction force between the elephant's back feet and the ground. Use the following information and calculate the magnitude of the tension in the elephant's trunk T (m = 4540 kg, FN = rfs = 133 cm, rcg = 76.0 cm, r = 229 cm). Number +x Axis of rotation Units 60 165 30 W TTFN cg 10° Michael Poliza/Caters News Agencyarrow_forward
- A. Explain why placing your hands behind your head rather than placing them on your stomach makes sit-ups more difficult. B. Explain why it is easier (it requires a smaller force) to open a large jar than a small one.arrow_forwardA ladder of negligible mass composed of two ?-long rails that are hinged at the top, is placed on top of a frictionless floor. A metal bar, connecting both rails halfway up the ladder is placed so that the two rails make an angle of ?= 44.0◦ at the apex. Lastly, a ? = 4.40[kg] block is placed 2/3 of the way up the ladder, as shown.A. What's the magnitude of the tension in the metal bar?B. What's the magnitude of the normal force exerted on the bottom right side of the ladder?C. What's the magnitude of the normal force exerted on the bottom left side of the ladder?D. What's the magnitude of the force the right side of the ladder exerts on its left side?arrow_forwardTwo blocks rest on a horizontal frictionless surface as shown. The surface between the top and bottom blocks is roughened so that there is no slipping between the two blocks. A 45-N force is applied to the bottom block as suggested in the figure. What is the acceleration of the "two block" system? 5 kg 45 N 10 kg 6. 2 3 1 15arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Newton's First Law of Motion: Mass and Inertia; Author: Professor Dave explains;https://www.youtube.com/watch?v=1XSyyjcEHo0;License: Standard YouTube License, CC-BY