Physics (5th Edition)
5th Edition
ISBN: 9780321976444
Author: James S. Walker
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 7, Problem 77GP
Predict/Calculate A pitcher accelerates a 0.14-kg hardball from rest to 42.5 m/s in 0.060 s. (a) How much work does the pitcher do on the ball? (b) What is the pitcher’s power output during the pitch? (c) Suppose the ball reaches 42/5 m/s in less than 0.060 s. Is the power produced by the pitcher in this case more than, less than, or the same as the power found in part (b)? Explain.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Physics (5th Edition)
Ch. 7.1 - Enhance Your Understanding (Answers given at the...Ch. 7.2 - Enhance Your Understanding (Answers given at the...Ch. 7.3 - As an object moves along the positive x axis the...Ch. 7.4 - Enhance Your Understanding (Answers given at the...Ch. 7 - Is it possible to do work on an object that...Ch. 7 - A friend makes the statement, Only the total force...Ch. 7 - A friend makes the statement, A force that is...Ch. 7 - The net work done on a certain object is zero What...Ch. 7 - Give an example of a frictional force doing...Ch. 7 - A ski boat moves with constant velocity Is the net...
Ch. 7 - A package rests on the floor of an elevator that...Ch. 7 - An object moves with constant velocity Is it safe...Ch. 7 - Engine 1 does twice the work of engine 2. Is it...Ch. 7 - Engine 1 produces twice the power of engine 2. Is...Ch. 7 - A pendulum bob swings from point I to point II...Ch. 7 - A pendulum bob swings from point II to point III...Ch. 7 - A farmhand pushes a 26-kg bale of hay 3.9 m across...Ch. 7 - Children in a tree house lift a small dog in a...Ch. 7 - Early one October, you go to a pumpkin patch to...Ch. 7 - The coefficient of kinetic friction between a...Ch. 7 - BIO Peristaltic Work The human snail intestine...Ch. 7 - Predict/Calculate A tow rope, parallel to the...Ch. 7 - A child pulls a friend in a little red wagon with...Ch. 7 - A 57-kg packing crate is pulled with constant...Ch. 7 - Predict/Calculate To clean a floor, a janitor...Ch. 7 - A small plane tows a glider at constant speed and...Ch. 7 - As a snowboarder descends a mountain slope,...Ch. 7 - A young woman on a skateboard is pulled by a rope...Ch. 7 - To keep her dog from running away while she talks...Ch. 7 - Water skiers often ride to one side of the center...Ch. 7 - A pitcher throws a ball at 90 mi/h and the catcher...Ch. 7 - How much work is needed for a 73 kg runner to...Ch. 7 - Skylabs Reentry When Skylab reentered the Earths...Ch. 7 - Predict/Calculate A 9.50-g bullet has a speed of...Ch. 7 - The energy required to increase the speed of a...Ch. 7 - Predict/Explain The work W0 accelerates a car...Ch. 7 - Car A has a mass m and a speed u, car B has a mass...Ch. 7 - Predict/Calculate A 0.14-kg pinecone falls 16 m to...Ch. 7 - In the previous problem (a) how much work was done...Ch. 7 - At t = 1.0s, a 0.55-kg object is tailing with a...Ch. 7 - After hitting a long fly ball that goes over the...Ch. 7 - Predict/Calculate A 1100-kg car coasts on a...Ch. 7 - A 65-kg bicyclist rides his 8 8-kg bicycle with a...Ch. 7 - A block of mass m and speed U collides with a...Ch. 7 - A spring with a force constant of 3.5 104 N/m is...Ch. 7 - Initially sliding with a speed of 4.1 m/s, a...Ch. 7 - The force shown in Figure 7-21 moves an object...Ch. 7 - An object is acted on by the force shown in Figure...Ch. 7 - To compress spring 1 by 0 20 m takes 150 J of...Ch. 7 - Predict/Calculate It takes 180 J of work to...Ch. 7 - The force shown in Figure 7-22 acts on a 1.3-kg...Ch. 7 - A block is acted on by a force that varies as (2.0...Ch. 7 - Section 7-4 Power 42 CE Fore F1 does 5 J of work...Ch. 7 - BIO Climbing the Empire State Building A new...Ch. 7 - Calculate the power output of a 14-mg fly as it...Ch. 7 - An ice cube is placed in a microwave oven. Suppose...Ch. 7 - Your car produces about 34 kw of power to maintain...Ch. 7 - You raise a bucket of water from the bottom of a...Ch. 7 - BIO Salmon Migration As Chinook salmon swim...Ch. 7 - In order to keep a leaking ship from sinking, it...Ch. 7 - Predict/Calculate A kayaker paddles with a power...Ch. 7 - BIO Human-Powered Flight Human-powered aircraft...Ch. 7 - Predict/Calculate Beating to Windward A sailboat...Ch. 7 - Predict/Calculate A grandfather clock is powered...Ch. 7 - Prob. 54PCECh. 7 - CE As the three small sailboats shown in Figure...Ch. 7 - CE Predict/Explain A car is accelerated by a...Ch. 7 - CE Car 1 has four limes the mass of car 2, but...Ch. 7 - BIO Muscle Cells Biological muscle cells can be...Ch. 7 - A small motor runs a lift that raises a load of...Ch. 7 - You push a 67-kg box across a door where the...Ch. 7 - A 1300-kg elevator is lifted at a constant speed...Ch. 7 - CE The work W0 is required to accelerate a car...Ch. 7 - After a tornado a 0.55-g straw was found embedded...Ch. 7 - You throw a glove straight upward to celebrate a...Ch. 7 - The water skier in Figure 7-20 is at an angle of...Ch. 7 - Predict/Calculate A sled with a mass of 5.80 kg is...Ch. 7 - Predict/Calculate A 0.19-kg apple falls from a...Ch. 7 - A boy pulls a bag of baseball bats across a ball...Ch. 7 - At the instant it leaves the players hand after a...Ch. 7 - The force shown in Figure 7-25 acts on an object...Ch. 7 - A Compound Bow A compound bow in archery allows...Ch. 7 - A Compound Versus a Simple Bow The compound bow in...Ch. 7 - Calculate the power output of a 0.42-g spider as...Ch. 7 - Cookie Power To make a batch of cookies, you mix...Ch. 7 - Predict/Calculate A pitcher accelerates a 0.14-kg...Ch. 7 - BIO Brain Power The human brain consumes about 22...Ch. 7 - Meteorite On October 9, 1992, a 27-pound meteorite...Ch. 7 - BIO Powering a Pigeon A pigeon in flight...Ch. 7 - Springs in Series Two springs, with force...Ch. 7 - Springs in Parallel Two springs, with force...Ch. 7 - A block rests on a horizontal frictionless...Ch. 7 - BIO Microraptor gui: The Biplane Dinosaur The...Ch. 7 - BIO Microraptor gui: The Biplane Dinosaur The...Ch. 7 - BIO Microraptor gui: The Biplane Dinosaur The...Ch. 7 - BIO Microraptor gui: The Biplane Dinosaur The...Ch. 7 - Referring to Figure 7-15 Suppose the block has a...Ch. 7 - Predict/Calculate Referring to Figure 7-15 In the...Ch. 7 - Predict/Calculate Referring 10 Example 7-15...
Additional Science Textbook Solutions
Find more solutions based on key concepts
A gas undergoes an adiabatic compression during which its volume drops to half its original value. If the gas p...
Essential University Physics: Volume 1 (3rd Edition)
14.72 CP SHM of a Floating Object. An object with height h, mass M, and a uniform cross-sectional area A floats...
University Physics (14th Edition)
What is Newton’s universal law of gravitation? Write it in equation form, and clearly explain what the equation...
Life in the Universe (4th Edition)
Express the unit vectors in terms of (that is, derive Eq. 1.64). Check your answers several ways Also work o...
Introduction to Electrodynamics
An electromagnet produces a magnetic field of magnitude 1.5 T throughout a cylindrical region of radius 6.0 cm....
University Physics Volume 2
Does choosing a pivot point in an equilibrium problem mean that something is necessarily going to rotate about ...
Essential University Physics (3rd Edition)
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
- Spiderman, whose mass is 80.0 kg, is dangling on the free end of a 12.0-m-long rope, the other end of which is fixed to a tree limb above. By repeatedly bending at the waist, he is able to get the rope in motion, eventually getting it to swing enough that he can reach a ledge when the rope makes a 60.0 angle with the vertical. How much work was done by the gravitational force on Spiderman in this maneuver?arrow_forwardReview. You can think of the workkinetic energy theorem as a second theory of motion, parallel to Newtons laws in describing how outside influences affect the motion of an object. In this problem, solve parts (a), (b), and (c) separately from parts (d) and (e) so you can compare the predictions of the two theories. A 15.0-g bullet is accelerated from rest to a speed of 780 m/s in a rifle barrel of length 72.0 cm. (a) Find the kinetic energy of the bullet as it leaves the barrel. (b) Use the workkinetic energy theorem to find the net work that is done on the bullet. (c) Use your result to part (b) to find the magnitude of the average net force that acted on the bullet while it was in the barrel. (d) Now model the bullet as a particle under constant acceleration. Find the constant acceleration of a bullet that starts from rest and gains a speed of 780 m/s over a distance of 72.0 cm. (e) Modeling the bullet as a particle under a net force, find the net force that acted on it during its acceleration. (f) What conclusion can you draw from comparing your results of parts (c) and (e)?arrow_forwardEstimate the kinetic energy of a 90,000-ton aircraft carrier moving at a speed of at 30 knots. You will need to look up the definition of a nautical mile to use in converting the unit for speed, where 1 knot equals 1 nautical mile per hour.arrow_forward
- A hummingbird is able to hover because, as the wings move downward, they exert a downward force on the air. Newtons third law tells us that the air exerts an equal and opposite force (upward) on the wings. The average of this force must be equal to the weight of the bird when it hovers. If the wings move through a distance of 3.5 cm with each stroke, and the wings beat 80 times per second, determine the work performed by the wings on the air in 1 m if the mass of the hummingbird is 3.0 g.arrow_forwardCalculate the power output in watts and horsepower of a shot-putter who takes 1.20 s to accelerate the 7.27-kg shot from rest to 14.0 m/s, while raising it 0.800 m. (Do not include the power produced to accelerate his body.) Figure 7.42 Shot putter at the Dornoch Highland Gathering in 2007. (credit: John Haslam, Flickr)arrow_forwardGive an example of a situation in which there is a force and a displacement, but the force does no work. Explain why it does no work.arrow_forward
- Physics Review An athlete lifts a 175-kg barbell through a vertical displacement of 2.00 m, requiring 4.30 s for the lift. (a) Calculate the average mechanical power he must deliver to the barbell during the lift. (b) For a short period he lifts the barbell at a constant speed of 0.600 m/s. What instantaneous power does he deliver so the barbell during the time? (See Section 5.6)arrow_forwardHow much work is done by the boy pulling his sister 30.0 m in a wagon as shown in Figure 7.36? Assume no friction acts on the wagon. Figure 7.36 The boy does work on the system of the wagon and the child when he pulls them as shown.arrow_forwardTwo toboggans (with riders) of the same mass are at rest on top of a steep hill. As they slide down the hill, toboggan A takes a straight path down the slope while toboggan B winds back and forth along a more gently sloping path. Toboggan A makes the trip in half the time of toboggan B. (a) Compare the work done by gravity on each toboggan. (b) Compare the average power delivered by gravity on the two toboggans.arrow_forward
- Give an example of a situation in which there is a force and a displacement, but the force does no work. Explain why it does no work.arrow_forwardCalculate the work done by an 85.0-kg man who pushes a crate 4.00 m up along a ramp that makes an angle of 20.0° with the horizontal. (See Figure 7.35.) He exerts a force of 500 N on the crate parallel to the ramp and moves at a constant speed. Be certain to include the work he does on the crate and on his body to get up the ramp. Figure 7.35 A man pushes a crate up a ramp.arrow_forwardDiscuss the work done by a pitcher throwing a baseball. What is the approximate distance through which the force acts as the ball is thrown?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegeCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Mechanical work done (GCSE Physics); Author: Dr de Bruin's Classroom;https://www.youtube.com/watch?v=OapgRhYDMvw;License: Standard YouTube License, CC-BY