Physics for Scientists and Engineers with Modern Physics
4th Edition
ISBN: 9780131495081
Author: Douglas C. Giancoli
Publisher: Addison-Wesley
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Textbook Question
Chapter 4, Problem 25P
(III) The 100-m dash can be run by the best sprinters in 10.0 s. A 66-kg sprinter accelerates uniformly for the first 45 m to reach top speed, which he maintains for the remaining 55 m. (a) What is the average horizontal component of force exerted on his feet by the ground during acceleration? (b) What is the speed of the sprinter over the last 55 m of the race (i.e., his top speed)?
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Chapter 4 Solutions
Physics for Scientists and Engineers with Modern Physics
Ch. 4.4 - Suppose you watch a cup slide on the (smooth)...Ch. 4.5 - Return to the first Chapter-Opening Question, page...Ch. 4.5 - A massive truck collides head-on with a small...Ch. 4.5 - If you push on a heavy desk, does it always push...Ch. 4.7 - A 10.0-kg box is dragged on a horizontal...Ch. 4 - Why does a child in a wagon seem to fall backward...Ch. 4 - A box rests on the (frictionless) bed of a truck....Ch. 4 - If the acceleration of an object is zero, are no...Ch. 4 - If an object is moving, is it possible for the net...Ch. 4 - Only one force acts on an object. Can the object...
Ch. 4 - When a golf ball is dropped to the pavement, it...Ch. 4 - If you walk along a log floating on a lake, why...Ch. 4 - Why might your foot hurt if you kick a heavy desk...Ch. 4 - When you are running and want to slop quickly, you...Ch. 4 - (a) Why do you push down harder on the pedals of a...Ch. 4 - A father and his young daughter are ice skating....Ch. 4 - Suppose that you are standing on a cardboard...Ch. 4 - A stone hangs by a fine thread from the ceiling,...Ch. 4 - The force of gravity on a 2-kg rock is twice as...Ch. 4 - Would a spring scale carried to the Moon give...Ch. 4 - You pull a box with a constant force across a...Ch. 4 - When an object falls freely under the influence of...Ch. 4 - Compare the effort (or force) needed to lift a...Ch. 4 - Which of the following objects weighs about 1 N:...Ch. 4 - According to Newtons third law. each team in a tug...Ch. 4 - When you stand still on the ground, how large a...Ch. 4 - Whiplash sometimes results from an automobile...Ch. 4 - Mary exerts an upward force of 40N to hold a bag...Ch. 4 - A bear sling, Fig. 430, in used in some national...Ch. 4 - (I) What force is needed to accelerate a child on...Ch. 4 - (1) A net force of 265N accelerates a bike and...Ch. 4 - (I) What is the weight of a 68-kg astronaut (a) on...Ch. 4 - (I) How much tension must a rope withstand if it...Ch. 4 - (II) Superman must stop a 120-km/h train in 150 m...Ch. 4 - (II) What average force is required to stop a...Ch. 4 - (II) Estimate the average force exerted by a...Ch. 4 - (II) A 0.140-kg baseball traveling 35.0 m/s...Ch. 4 - (II) A fisherman yanks a fish vertically out of...Ch. 4 - (II) A 20.0-kg box rests on a table. (a) What is...Ch. 4 - (II) What average force is needed to accelerate a...Ch. 4 - (II) How much tension must a cable withstand if it...Ch. 4 - (II) A 14.0-kg bucket is lowered vertically by a...Ch. 4 - (II) A particular race car can cover a...Ch. 4 - (II) A 75-kg petty thief wants to escape from a...Ch. 4 - (II) An elevator (mass 4850 kg) is to he designed...Ch. 4 - (II) Can cars stop on a dime? Calculate the...Ch. 4 - (II) A person stands on a bathroom scale in a...Ch. 4 - (II) High-speed elevators function under two...Ch. 4 - (II) Using focused laser light, optical tweezers...Ch. 4 - (II) A rocket with a mass of 2.75 106 kg exerts a...Ch. 4 - (II) (a) What is the acceleration of two falling...Ch. 4 - (II) An exceptional standing jump would raise a...Ch. 4 - (II) The cable supporting a 2125-kg elevator has a...Ch. 4 - (III) The 100-m dash can be run by the best...Ch. 4 - (III) A person jumps from the roof of a house...Ch. 4 - (I) A box weighing 77.0 N rests on atable. A rope...Ch. 4 - (I) Draw the free-body diagram for a basketball...Ch. 4 - (I) Sketch the tree body diagram of a baseball (a)...Ch. 4 - (I) A 650-N force acts in a northwesterly...Ch. 4 - (II) Christian is making a Tyrolean traverse as...Ch. 4 - (II) A window washer pulls herself upward using...Ch. 4 - (II) One 3.2-kg paint bucket is hanging by a...Ch. 4 - (II) The cords accelerating the buckets in Problem...Ch. 4 - (II) Two snowcats in Antarctica are towing a...Ch. 4 - (II) A train locomotive is pulling two cars of the...Ch. 4 - (II) The two forces F1 and F2 shown in Fig. 4-40a...Ch. 4 - (II) At the instant a race began, a 65-kg sprinter...Ch. 4 - (II) A mass m is at rest on a horizontal...Ch. 4 - Prob. 40PCh. 4 - (II) Uphill escape ramps are sometimes provided to...Ch. 4 - (II) A child on a sled reaches the bottom of a...Ch. 4 - (II) A skateboarder, with an initial speed of...Ch. 4 - (II) As shown in Fig. 4-41, five balls (masses...Ch. 4 - (II) A 27-kg chandelier hangs from a ceiling on a...Ch. 4 - (II) Three blocks on a frictionless horizontal...Ch. 4 - (II) Redo Example 413 but (a) set up the equations...Ch. 4 - (II) The block shown in Fig. 4-43 has mass m = 7.0...Ch. 4 - (II) A block is given an initial speed of 4.5 m/s...Ch. 4 - (II) An object is hanging by a string from your...Ch. 4 - (II) Figure 4-45 shows a block (mass mA) on a...Ch. 4 - (II) (a) If mA = 13.0 kg and mB = 5.0 kg in Fig....Ch. 4 - (III) Determine a formula for the acceleration of...Ch. 4 - (III) Suppose the pulley in Fig. 446 is suspended...Ch. 4 - (III) A small block of mass m rests on the sloping...Ch. 4 - (III) The double Atwood machine shown in Fig. 4-48...Ch. 4 - (III) Suppose two boxes on a frictionless table...Ch. 4 - (III) The two masses shown in Fig, 450 are each...Ch. 4 - (III) Determine a formula for the magnitude of the...Ch. 4 - (III) A particle of mass m, initially at rest at x...Ch. 4 - (III) A heavy steel cable of length and mass M...Ch. 4 - A person has a reasonable chance of surviving an...Ch. 4 - A 2.0-kg purse is dropped 58 m from the top of the...Ch. 4 - Toms hang glider supports his weight using the six...Ch. 4 - A wet bar of soap (m = 150 g) slides freely down a...Ch. 4 - A cranes trolley at point P in Fig. 4-53 moves for...Ch. 4 - A block (mass mA) lying on a fixed frictionless...Ch. 4 - (a) In Fig. 454, if mA = mB = 1.00 kg and 33.0,...Ch. 4 - The masses mA and mB slide on the smooth...Ch. 4 - A 75.0-kg person stands on a scale in an elevator....Ch. 4 - A city planner is working on the redesign of a...Ch. 4 - If a bicyclist of mass 65 kg (including the...Ch. 4 - A bicyclist can coast down a 5.0 hill at a...Ch. 4 - Francesca dangles her watch from a thin piece of...Ch. 4 - (a) What minimum force F is needed to lift the...Ch. 4 - In the design of a supermarket, there are to be...Ch. 4 - A jet aircraft is accelerating at 3.8m/s2 as it...Ch. 4 - A 7650-kg helicopter accelerates upward at 0.80...Ch. 4 - A super high-speed 14-car Italian train has a mass...Ch. 4 - A fisherman in a boat is using a 10-lb test...Ch. 4 - An elevator in a tall building is allowed to reach...Ch. 4 - Two rock climbers, Bill and Karen, use safety...Ch. 4 - Three mountain climbers who are roped together in...Ch. 4 - A doomsday asteroid with a mass of 1.0 1010kg is...Ch. 4 - A 450-kg piano is being unloaded from a truck by...Ch. 4 - Consider the system shown in Fig. 462 with mA =...Ch. 4 - A 1.5-kg block rests on top of a 7.5-kg block...Ch. 4 - You are driving home in your 750-kg car at 15 m/s....Ch. 4 - (II) A large crate of mass 1500 kg starts sliding...
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