Physics
7th Edition
ISBN: 9780321733627
Author: Douglas C. Giancoli
Publisher: PEARSON
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Textbook Question
Chapter 4, Problem 8Q
(a) Why do you push down harder on the pedals of a bicycle when first starting out than when moving at constant speed? (b) Why do you need to pedal at all when cycling at constant speed?
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Chapter 4 Solutions
Physics
Ch. 4 - A 150-kg football player collides head-on with a...Ch. 4 - A line by the poet T. S. Eliot (from Murder in the...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 - Prob. 3QCh. 4 - If the acceleration of an object is zero, are no...Ch. 4 - Prob. 5QCh. 4 - Prob. 6QCh. 4 - Prob. 7QCh. 4 - (a) Why do you push down harder on the pedals of a...
Ch. 4 - A stone hangs by a fine thread from the ceiling,...Ch. 4 - Prob. 10QCh. 4 - Prob. 11QCh. 4 - Prob. 12QCh. 4 - Prob. 13QCh. 4 - Prob. 14QCh. 4 - Prob. 15QCh. 4 - Prob. 16QCh. 4 - Prob. 17QCh. 4 - Prob. 18QCh. 4 - Prob. 19QCh. 4 - A block is given a brief push so that it slides up...Ch. 4 - Prob. 21QCh. 4 - Prob. 22QCh. 4 - A truck is traveling horizontally to the right...Ch. 4 - You are trying to push your stalled car. Although...Ch. 4 - Matt, in the foreground of Fig. 4-39, is able to...Ch. 4 - A bear sling, Fig. 4-40, is used in some national...Ch. 4 - What causes the boat in Fig. 4-41 to move forward?...Ch. 4 - A person stands on a scale in an elevator. His...Ch. 4 - When a skier skis down a hill, the normal force...Ch. 4 - A golf ball is hit with a golf club. While the...Ch. 4 - Suppose an object is accelerated by a force of 100...Ch. 4 - You are pushing a heavy box across a rough floor....Ch. 4 - Prob. 11MCQCh. 4 - The normal force on an extreme skier descending a...Ch. 4 - To pull an old stump out of the ground, you and a...Ch. 4 - What force is needed to accelerate a sled (mass =...Ch. 4 - Prob. 2PCh. 4 - How much tension must a rope withstand if it is...Ch. 4 - According to a simplified model of a mammalian...Ch. 4 - Superman must stop a 120-km/h train in 150 m to...Ch. 4 - A person has a reasonable chance of surviving an...Ch. 4 - What average force is required to stop a 950-kg...Ch. 4 - Prob. 8PCh. 4 - Prob. 9PCh. 4 - Prob. 10PCh. 4 - Prob. 11PCh. 4 - Prob. 12PCh. 4 - Prob. 13PCh. 4 - Prob. 14PCh. 4 - Prob. 15PCh. 4 - Prob. 16PCh. 4 - Prob. 17PCh. 4 - Prob. 18PCh. 4 - Prob. 19PCh. 4 - A box weighing 77.0 N rests on a table. A rope...Ch. 4 - Figure 4-46
Problem 21.
21. (I) Draw the free-body...Ch. 4 - Prob. 22PCh. 4 - Arlene is to walk across a “high wire" strung...Ch. 4 - A window washer pulls herself upward using the...Ch. 4 - One 3.2-kg paint bucket is hanging by a massless...Ch. 4 - Prob. 26PCh. 4 - A train locomotive is pulling two cars of the same...Ch. 4 - Prob. 28PCh. 4 - At the instant a race began, a 65-kg sprinter...Ch. 4 - A 27-kg chandelier hangs from a ceiling on a...Ch. 4 - Prob. 31PCh. 4 - Figure 4-53 [shows a block (mass mA) on a smooth...Ch. 4 - Prob. 33PCh. 4 - Prob. 34PCh. 4 - 35. (Ill) Suppose the pulley in Fig. 4-55 is...Ch. 4 - Prob. 36PCh. 4 - A force of 35.0 N is required to start a 6.0-kg...Ch. 4 - Prob. 38PCh. 4 - Prob. 39PCh. 4 - Prob. 40PCh. 4 - Prob. 41PCh. 4 - A box is given a push so that it slides across the...Ch. 4 - Prob. 43PCh. 4 - Prob. 44PCh. 4 - Prob. 45PCh. 4 - 46. (II) For the system of Fig. 4-32 (Example...Ch. 4 - Prob. 47PCh. 4 - Prob. 48PCh. 4 - Prob. 49PCh. 4 - A person pushes a 14.0-kg lawn mower at constant...Ch. 4 - Prob. 51PCh. 4 - (a) A box sits at rest on a rough 33° inclined...Ch. 4 - Prob. 53PCh. 4 - Prob. 54PCh. 4 - Prob. 55PCh. 4 - A 25.0-kg box is released on a 27° incline and...Ch. 4 - Prob. 57PCh. 4 - Prob. 58PCh. 4 - The crate shown in Fig. 4-60 lies on a plane...Ch. 4 - A crate is given an initial speed of 3.0 m/s up...Ch. 4 - Prob. 61PCh. 4 - Prob. 62PCh. 4 - The coefficient of kinetic friction for a 22-kg...Ch. 4 - On an icy day, you worry about parking your car in...Ch. 4 - Two masses mA= 2.0 kg and mB= 5.0 kg are on...Ch. 4 - Prob. 66PCh. 4 - Prob. 67PCh. 4 - A 2.0-kg purse is dropped from the top of the...Ch. 4 - Prob. 69GPCh. 4 - 70. A 75.0-kg person stands on a scale in an...Ch. 4 - Prob. 71GPCh. 4 - Prob. 72GPCh. 4 - Prob. 73GPCh. 4 - Prob. 74GPCh. 4 - Prob. 75GPCh. 4 - (a) What minimum force F is needed to lift the...Ch. 4 - Prob. 77GPCh. 4 - A jet aircraft is accelerating at 3.8 m/s2 as it...Ch. 4 - Prob. 79GPCh. 4 - Prob. 80GPCh. 4 - Prob. 81GPCh. 4 - Prob. 82GPCh. 4 - Prob. 83GPCh. 4 - Prob. 84GPCh. 4 - Prob. 85GPCh. 4 - Prob. 86GPCh. 4 - Prob. 87GPCh. 4 - Prob. 88GPCh. 4 - Prob. 89GPCh. 4 - Prob. 90GPCh. 4 - A 72-kg water skier is being accelerated by a ski...Ch. 4 - Prob. 92GPCh. 4 - Prob. 93GPCh. 4 - Prob. 94GPCh. 4 - Prob. 95GPCh. 4 - Prob. 96GPCh. 4 - Prob. 97GP
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- Why is it difficult to walk on the wet marble floor?arrow_forwardYou want to run up a hill starting from standstill. The hill is at an angle of 30 degrees with respect to hortizontal and has a coefficient of static friction of 0.3. How long will it take to reach a top speed of 25.2km/h?arrow_forwardA car traveling at 60 mph (97,000 m/hr) can stop in 48 m on a level road. Determine the coefficient of friction between the tires and the road. Assume that the car starts skidding the moment the driver hits the brakes.arrow_forward
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