University Physics with Modern Physics (14th Edition)
14th Edition
ISBN: 9780321973610
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
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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)?
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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)?
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?
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...
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