PHYSICS F/SCI.+ENGR.W/MODERN...-W/WKBK.
4th Edition
ISBN: 9780134758053
Author: Knight
Publisher: PEARSON
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Chapter 6, Problem 42EAP
Seat belts and air bags save lives by reducing the forces exerted on the driver and passenger in an automobile collision. Cars are designed with a “crumple zone” in the front of the car. In the event of an impact, the passenger compartment decelerates over a distance of about 1 m as the front of the car crumples. An occupant restrained by seat belts and air bags decelerates with the car. By contrast, an unrestrained occupant keeps moving forward with no loss of speed (Newton's first law!) until hitting the dashboard or windshield. These are unyielding surfaces, and the unfortunate occupant then decelerates over a distance of only about 5 mm.
a. A 60 kg person is in a head-on collision. The car's speed at impact is 15 m/s. Estimate the net force on the person if he or she is wearing a seat belt and if the air bag deploys.
b. Estimate the net force that ultimately stops the person if he or she is not restrained by a seat belt or air bag.
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Chapter 6 Solutions
PHYSICS F/SCI.+ENGR.W/MODERN...-W/WKBK.
Ch. 6 - Are the objects described here in equilibrium...Ch. 6 - A ball tosses straight up has v = 0 at its highest...Ch. 6 - Kat, Matt, and Nat are arguing about why a physics...Ch. 6 - If you know all of the forces acting on a moving...Ch. 6 - An elevator, hanging from a single cable, moves...Ch. 6 - An elevator, hanging from a single cable, moves...Ch. 6 - Are the following statements true or false?...Ch. 6 -
8. An astronaut takes his bathroom scale to the...Ch. 6 -
9. The four balls in FIGURE Q6.9 have been...Ch. 6 - Prob. 10CQ
Ch. 6 - Prob. 11CQCh. 6 - A hand presses down on the book in FIGURE Q6.12....Ch. 6 - Boxes A and B in FIGURES Q6.13 both remain at...Ch. 6 - Suppose you push a hockey puck of mass m across...Ch. 6 - A block pushed along the floor with velocity...Ch. 6 - A crate of fragile dishes is in the back of a...Ch. 6 - Five balls move through the air as shown in FIGURE...Ch. 6 - The three ropes in FIGURE EX6.1 are tied to a...Ch. 6 - The three ropes in FIGURE EX6.2 are tied to a...Ch. 6 - A football coach sits on a sled while two of his...Ch. 6 - A 20 kg loudspeaker is suspended 2.0 m below the...Ch. 6 - A 65 kg gymnast wedges himself between two closely...Ch. 6 - A construction worker with a weight of 850 N...Ch. 6 - In an electricity experiment, a 1.0 g plastic ball...Ch. 6 - The forces in FIGURE EX6.8 act on a 2.0 kg object....Ch. 6 - The forces in FIGURE EX6.9 act on a 2.0 kg object....Ch. 6 - FIGURE EX6.10 shows the velocity graph of a 2.0 kg...Ch. 6 - FIGURE EX6.11 shows the force acting on a 2.0 kg...Ch. 6 - A horizontal rope is tied to a 50 kg box on...Ch. 6 - A 50 kg box hangs from a rope. What is the tension...Ch. 6 - A 2.0 × 107 kg train applies its brakes with the...Ch. 6 - A 8.0 × 104 kg spaceship is at rest in deep space....Ch. 6 - The position of a 2.0 kg mass is given by x = (2t3...Ch. 6 - A woman has mass of 55 kg. a. What is her weight...Ch. 6 - It takes the elevator in a skyscraper 4.0 s to...Ch. 6 - Zach, whose mass is 80 kg, is in an elevator...Ch. 6 - What thrust does a 200 g model rocket need in...Ch. 6 - What thrust does a 200 g model rocket need in...Ch. 6 - A 20,000 kg rocket has a rocket motor that...Ch. 6 - The earth is 1.50 × 1011 m from the sun. The...Ch. 6 - Bonnie and Clyde are sliding a 300 kg bank safe...Ch. 6 - A stubborn, 120 kg mule sits down and refuses to...Ch. 6 - A 10 kg crate is placed on a horizontal conveyor...Ch. 6 - Bob is pulling a 30 kg filing cabinet with a force...Ch. 6 - A rubber-wheeled kg cart rolls down a 15° concrete...Ch. 6 - A 4000 kg truck is parked on a 15° slope. How big...Ch. 6 - A 1500 kg car skids to a halt on a wet road where...Ch. 6 - A 50,000 kg locomotive is traveling at 10 m/s when...Ch. 6 - You and your friend Peter are putting new shingles...Ch. 6 - An Airbus A320 jetliner has a takeoff mass of...Ch. 6 -
34. A medium-sized jet has a 3.8-m-diameter...Ch. 6 - A 75 kg skydiver can be modeled as a rectangular...Ch. 6 - A 6.5-cm-diameter ball has a terminal speed of 26...Ch. 6 - A 2.0 kg object initially at rest at the origin is...Ch. 6 - A 5.0 kg object initially at rest at the origin is...Ch. 6 - The 1000 kg steel beam in FIGURE P6.39 is...Ch. 6 - Henry, whose mass is 95 kg, stands on a bathroom...Ch. 6 - An accident victim with a broken leg is being...Ch. 6 - Seat belts and air bags save lives by reducing the...Ch. 6 - The piston of a machine exerts a constant force on...Ch. 6 - Compressed air is used to fire a 50 g ball...Ch. 6 - a. A rocket of mass m is launched straight up with...Ch. 6 - A rifle with a barrel length of 60 cm fires a 10 g...Ch. 6 - A truck with a heavy load has a total mass of 7500...Ch. 6 - An object of mass m is at rest at the top of a...Ch. 6 - Prob. 49EAPCh. 6 - A baggage handler drops your 10 kg suitcase onto a...Ch. 6 - A 2.0 kg wood block is launched up a wooden ramp...Ch. 6 - It’s a snowy day and you're pulling a friend along...Ch. 6 - A large box of mass M is pulled across a...Ch. 6 - Prob. 54EAPCh. 6 - You're driving along at 25 m/s with your aunt's...Ch. 6 - The 2.0 kg wood box in FIGURE P6.56 slides down a...Ch. 6 - A 1.0 kg wood block is pressed against a vertical...Ch. 6 - A person with compromised pinch strength in his...Ch. 6 - A ball is shot from a compressed-air gun at twice...Ch. 6 - Starting from rest, a 2500 kg helicopter...Ch. 6 - Astronauts in space "weigh" themselves by...Ch. 6 - A particle of mass m moving along the x-axis...Ch. 6 - At t = 0, an object of mass m is at rest at x = 0...Ch. 6 - At t = 0, an object of mass m is at rest at x = 0...Ch. 6 - Prob. 65EAPCh. 6 - A 60 kg skater is gliding across frictionless ice...Ch. 6 - Prob. 67EAPCh. 6 - Problems 68 and 69 show a free-body diagram. For...Ch. 6 - Problems 68 and 69 show a free-body diagram. For...Ch. 6 - Prob. 70EAPCh. 6 - In Problems 70 through 72 you are given the...Ch. 6 - In Problems 70 through 72 you are given the...Ch. 6 - A block of mass m is at rest at the origin at t =...Ch. 6 - A spring-loaded toy gun exerts a variable force on...Ch. 6 - FIGURE CP6.7S shows an accelerometer, a device for...Ch. 6 - An object moving in a liquid experiences a linear...Ch. 6 - Prob. 77EAPCh. 6 - An object with cross section A is shot...
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