University Physics with Modern Physics (14th Edition)
14th Edition
ISBN: 9780321973610
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 4, Problem 4.8E
You walk into an elevator, step onto a scale, and push the “up” button. You recall that your normal weight is 625 N. Draw a free-body diagram, (a) When the elevator has an upward acceleration of magnitude 2.50 m/s2, what does the scale read? (b) If you hold a 3.85-kg package by a light vertical string, what will be the tension in this string when the elevator accelerates as in part (a)?
Expert Solution & Answer
Learn your wayIncludes step-by-step video
schedule03:13
Students have asked these similar questions
You walk into an elevator, step onto a scale, and push the “up” button. You also recall that your normal weight is 625 N. Start answering each of the following questions by drawing a free body diagram. (a) If the elevator has an acceleration of magnitude 2.5 m/s2 , what does the scale read? (b) If you start holding a 3.85-kg package by a light vertical string, what will be the tension in this string once the elevator begins accelerating?
A lamp hangs vertically from a cord in a descending elevator that decelerates at 1.9 m/s2. (a) If the tension in the cord is 89 N, what is the lamp's mass? (b) What is the cord's tension when the elevator ascends with an upward acceleration of 1.9 m/s2?
You walk into an elevator, step onto a scale, and push the “up” button. You recall that your normal weight is 625 N. Draw a free-body diagram. (a) When the elevator has an upward acceleration of magnitude 2.50 m/s2, what does the scale read? (b) If you hold a 3.85 kg package by a light vertical string, what will be the tension in this string when the elevator accelerates as in part (a)?
Chapter 4 Solutions
University Physics with Modern Physics (14th Edition)
Ch. 4.1 - Figure 4.5 shows a force F acting on a crate. With...Ch. 4.2 - In which of the following situations is there zero...Ch. 4.3 - Rank the following situations in order of the...Ch. 4.4 - Prob. 4.4TYUCh. 4.5 - You are driving a car on a country road when a...Ch. 4 - Can a body be in equilibrium when only one force...Ch. 4 - A ball thrown straight up has zero velocity at its...Ch. 4 - A helium balloon hovers in midair, neither...Ch. 4 - When you fly in an airplane at night in smooth...Ch. 4 - If the two ends of a rope in equilibrium are...
Ch. 4 - You tie a brick lo the end of a rope and whirl the...Ch. 4 - When a car stops suddenly, the passengers tend to...Ch. 4 - Some people say that the force of inertia (or...Ch. 4 - A passenger in a moving bus with no windows...Ch. 4 - Suppose you chose the fundamental physical...Ch. 4 - Why is the earth only approximately an inertial...Ch. 4 - Does Newtons second law hold true for an observer...Ch. 4 - Some students refer to the quantity ma as the...Ch. 4 - The acceleration of a falling body is measured in...Ch. 4 - You can play catch with a softball in a bus moving...Ch. 4 - Students sometimes say that the force of gravity...Ch. 4 - Why can it hurt your foot more to kick a big rock...Ch. 4 - Its not the fall that hurts you; its the sudden...Ch. 4 - A person can dive into water from a height of 10 m...Ch. 4 - Why are cars designed to crumple in front and back...Ch. 4 - When a string barely strong enough lifts a heavy...Ch. 4 - A large crate is suspended from the end of a...Ch. 4 - Which feels a greater pull due to the earths...Ch. 4 - Why is it incorrect to say that 1.0 kg equals 2.2...Ch. 4 - A horse is hitched to a wagon. Since the wagon...Ch. 4 - True or false? You exert a push P on an object and...Ch. 4 - A large truck and a small compact car have a...Ch. 4 - When a car comes to a stop on a level highway,...Ch. 4 - A small compact car is pushing a large van that...Ch. 4 - Consider a tug-of-war between two people who pull...Ch. 4 - Boxes A and B are in contact on a horizontal,...Ch. 4 - A manual for student pilots contains this passage:...Ch. 4 - If your hands are wet and no towel is handy, you...Ch. 4 - If you squat down (such as when you examine the...Ch. 4 - When a car is hit from behind, the occupants may...Ch. 4 - In a head-on auto collision, passengers who are...Ch. 4 - In a head-on collision between a compact 1000-kg...Ch. 4 - Suppose you are in a rocket with no windows,...Ch. 4 - Two dogs pull horizontally on ropes attached to a...Ch. 4 - To extricate an SUV stuck in the mud, workmen use...Ch. 4 - BIO Jaw Injury. Due to a jaw injury, a patient...Ch. 4 - A man is dragging a trunk up the loading ramp of a...Ch. 4 - Forces F1 and F2act at a point. The magnitude of...Ch. 4 - An electron (mass = 9.11 1031 kg) leaves one end...Ch. 4 - A 68.5-kg skater moving initially at 2.40 m/s on...Ch. 4 - You walk into an elevator, step onto a scale, and...Ch. 4 - A box rests on a frozen pond, which serves as a...Ch. 4 - A dockworker applies a constant horizontal force...Ch. 4 - A hockey puck with mass 0.160 kg is at rest at the...Ch. 4 - A crate with mass 32.5 kg initially at rest on a...Ch. 4 - A 4.50-kg experimental cart undergoes an...Ch. 4 - A 2.75-kg cat moves in a straight line (the...Ch. 4 - A small 8.00-kg rocket burns fuel that exerts a...Ch. 4 - An astronauts pack weighs 17.5 N when she is on...Ch. 4 - Superman throws a 2400-N boulder at an adversary....Ch. 4 - BIO (a) An ordinary flea has a mass of 210 g. How...Ch. 4 - At the surface of Jupiters moon Io, the...Ch. 4 - A small car of mass 380 kg is pushing a large...Ch. 4 - BIO World-class sprinters can accelerate out of...Ch. 4 - The upward normal force exerted by the floor is...Ch. 4 - Boxes A and B are in contact on a horizontal,...Ch. 4 - A student of mass 45 kg jumps off a high diving...Ch. 4 - Section 4.6 Free-Body Diagrams 4.25Crates A and B...Ch. 4 - You pull horizontally on block B in Fig. F4.26,...Ch. 4 - A ball is hanging from a long siring that is tied...Ch. 4 - CP A .22-caliber rifle bullet traveling at 350 m/s...Ch. 4 - A chair of mass 12.0 kg is sitting on the...Ch. 4 - A large box containing your new computer sits on...Ch. 4 - CP A 5.60-kg bucket of water is accelerated upward...Ch. 4 - CP You have just landed on Planet X. You release a...Ch. 4 - Two adults and a child want to push a wheeled cart...Ch. 4 - CP An oil tankers engines have broken down, and...Ch. 4 - CP BIO A Standing Vertical Jump. Basketball player...Ch. 4 - CP An advertisement claims that a particular...Ch. 4 - BIO Human Biomechanics. The fastest pitched...Ch. 4 - BIO Human Biomechanics. The fastest served tennis...Ch. 4 - Two crates, one with mass 4.00 kg and the other...Ch. 4 - CP Two blocks connected by a light horizontal rope...Ch. 4 - CALC To study damage to aircraft that collide with...Ch. 4 - CP A 6.50-kg instrument is hanging by a vertical...Ch. 4 - BIO Insect Dynamics. The froghopper (Philaenus...Ch. 4 - A loaded elevator with very worn cables has a...Ch. 4 - CP After an annual checkup, you leave your...Ch. 4 - CP A nail in a pine board stops a 4.9-N hammer...Ch. 4 - CP Jumping to the Ground. A 75.0-kg man steps off...Ch. 4 - The two blocks in Fig. P4.48 are connected by a...Ch. 4 - CP Boxes A and B are connected to each end of a...Ch. 4 - CP Extraterrestrial Physics. You have landed on an...Ch. 4 - CP CALC A mysterious rocket-propelled object of...Ch. 4 - CALC The position of a training helicopter (weight...Ch. 4 - DATA The table gives automobile performance data...Ch. 4 - DATA An 8.00-kg box sits on a level floor. You...Ch. 4 - DATA You are a Starfleet captain going boldly...Ch. 4 - Prob. 4.56CPCh. 4 - BIO FORCES ON A DANCER'S BODY. Dancers experience...Ch. 4 - BIO FORCES ON A DANCERS BODY. Dancers experience...Ch. 4 - BIO FORCES ON A DANCER'S BODY. Dancers experience...Ch. 4 - The forces on a dancer can be measured directly...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Find the resistance of a heating coil that draws 4.8 A when the voltage across it is 120 V.
Essential University Physics: Volume 2 (3rd Edition)
Check Your Understanding The U.S. Air Force uses “10gs” (an acceleration equal to 109.8m/s2 ) as the maximum ac...
University Physics Volume 1
Unreasonable Results (a) What is the internal resistance of a 1.54-V dry cell that supplies 1.00 W of power to ...
College Physics
Explain all answers clearly, with complete sentences and proper essay structure if needed. An asterisk (*) desi...
Cosmic Perspective Fundamentals
The height of a certain hill (in feet) is given by , where y is the distance (in miles) north, x the distance e...
Introduction to Electrodynamics
A second experiment is performed in which glider D is fixed in place. Glider C is launched toward glider D with...
Tutorials in Introductory Physics
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
- A 3.00-kg object is moving in a plane, with its x and y coordinates given by x = 5t2 1 and y = 3t3 + 2, where x and y are in meters and t is in seconds. Find the magnitude of the net force acting on this object at t = 2.00 s.arrow_forwardIf a single constant force acts on an object that moves on a straight line, the objects velocity is a linear function of time. The equation v = vi + at gives its velocity v as a function of time, where a is its constant acceleration. What if velocity is instead a linear function of position? Assume that as a particular object moves through a resistive medium, its speed decreases as described by the equation v = vi kx, where k is a constant coefficient and x is the position of the object. Find the law describing the total force acting on this object.arrow_forwardA 3.00-kg block starts from rest at the top of a 30.0 incline and slides a distance of 2.00 m down the incline in 1.50 s. Find (a) the magnitude of the acceleration of the block, (b) the coefficient of kinetic friction between block and plane, (c) the friction force acting on the block, and (d) the speed of the block after it has slid 2.00 m.arrow_forward
- You bring a bathroom scale onto an elevator and press "up". Your mass is 65 kg. If the bathroom scale reads 750 N, (a) what is the acceleration of the elevator? You then press down and the acceleration downward is of the same magnitude. (b) While accelerating downward, you hold a small mass of 100 g attached to a string. What is the tension in the string? This elevator is in the new BU Data Science building where g = 10 m/s². Your work should include free body diagramsarrow_forwardConsider a person standing on a scale in an elevator. If the elevator accelerates upwards with an acceleration of 1.47 m/s2 and the person has a mass of 98.1 kg, what would the scale read? HINT: you need to take into account the acceleration due to gravity, as well as that of the elevator.arrow_forwardA body hangs from a spring balance supported from the roof of an elevator. If the elevator has an upward acceleration of 4 m/s2 the balance reads 45N, what is the true weight of the body?arrow_forward
- Someone is standing on a scale inside an elevator. When the elevator is accelerating upward, the scalereads 850 N; when the elevator is accelerating downward at the same acceleration, the scale reads 800N.Find the acceleration of the elevator, a = ?Find the mass of the person.Find the weight of this person. I know that Fn = mg + ma for upward and Fn = mg - ma for downward, but I am not sure how to find the middle ground that would be the acceleration?arrow_forwardA 2000kg elevator has a downward acceleration of 1.0 m/s/s. (a) What is the tension in its supporting cable? (b) The same elevator later has an upward acceleration of 1.5 m/s/s. What is the tension in the cable now?arrow_forwardA car skids to a stop on an icy road. The car has an initial velocity of 25.0 m/s and skids for 10.4 s before stopping. The mass of the car is unknown. Calculate the acceleration of the car. Draw the free-body diagram with the forces, but without their magnitudes. Find the coefficient of kinetic friction, ?k , between tires and the road. (Tricky. You don’t know the car’s mass, but you don’t have to know it. The mass cancels from the equation.)arrow_forward
- A mass M=99.2 kg is suspended by a massless string from the ceiling of a van which is moving with constant acceleration a, as shown in the figure below. (a)If the string makes an angle 20.0 degrees with respect to the vertical, what is the acceleration a of the van in m/s2? (b) What is the tension in the string in newtons?arrow_forward(a) If you ride in an elevator moving upward with constant speed, is your apparent weight greater than, less than, or equalto your actual weight, mg? (b) Which of the following is the best explanation for your prediction?I. The elevator is moving upward. This will cause a person to press down harder on the floor, giving an apparent weightgreater than mg.II. The elevator moves with zero acceleration, and therefore the apparent weight is equal to mg.III. Because the elevator is moving upward it is partially lifting the person, resulting in an apparent weight less than mgarrow_forwardWhen a parachute opens, the air exerts a large drag force on it. This upward force is initially greater than the weight of the sky diver and, thus, slows him down. Suppose the weight of the sky diver is 947 N and the drag force has a magnitude of 1065 N. The mass of the sky diver is 96.6 kg. Take upward to be the positive direction. What is his acceleration, including sign?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Newton's Second Law of Motion: F = ma; Author: Professor Dave explains;https://www.youtube.com/watch?v=xzA6IBWUEDE;License: Standard YouTube License, CC-BY