Problem Q6.1DQ: The sign of many physical quantities depends on the choice of coordinates. For example, ay for... Problem Q6.2DQ: An elevator is hoisted by its cables at constant speed. Is the total work done on the elevator... Problem Q6.3DQ: A rope tied to a body is pulled, causing the body to accelerate. But according to Newtons third law,... Problem Q6.4DQ: If it takes total work W to give an object a speed and kinetic energy K, starting from rest, what... Problem Q6.5DQ: If there is a net nonzero force on a moving object, can the total work done on the object be zero?... Problem Q6.6DQ: In Example 5.5 (Section 5.1), how does the work done on the bucket by the tension in the cable... Problem Q6.7DQ: In the conical pendulum of Example 5.20 (Section 5.4), which of the forces do work on the bob while... Problem Q6.8DQ: For the cases shown in Fig. Q6.8, the object is released from rest at the top and feels no friction... Problem Q6.9DQ: A force F is in the x-direction and has a magnitude that depends on x. Sketch a possible graph of F... Problem Q6.10DQ: Does a cars kinetic energy change more when the car speeds up from 10 to 15 m/s or from 15 to 20... Problem Q6.11DQ: A falling brick has a mass of 1.5 kg and is moving straight downward with a speed of 5.0 m/s. A... Problem Q6.12DQ: Can the total work done on an object during a displacement be negative? Explain. If the total work... Problem Q6.13DQ: A net force acts on an object and accelerates it from rest to a speed 1. In doing so, the force does... Problem Q6.14DQ: A truck speeding down the highway has a lot of kinetic energy relative to a stopped state trooper... Problem Q6.15DQ: You are holding a briefcase by the handle, with your arm straight down by your side. Does the force... Problem Q6.16DQ: When a book slides along a tabletop. the force of friction does negative work on it. Can friction... Problem Q6.17DQ: Time yourself while running up a flight of steps, and compute the average rate at which you do work... Problem Q6.18DQ: Fractured Physics. Many terms from physics are badly misused in everyday language. In both cases,... Problem Q6.19DQ: An advertisement for a portable electrical generating unit claims that the units diesel engine... Problem Q6.20DQ: A car speeds up while the engine delivers constant power. Is the acceleration greater at the... Problem Q6.21DQ: Consider a graph of instantaneous power versus time, with the vertical P-axis starting at P = 0.... Problem Q6.22DQ: A nonzero net force acts on an object. Is it possible for any of the following quantities to be... Problem Q6.23DQ: When a certain force is applied to an ideal spring, the spring stretches a distance x from its... Problem Q6.24DQ: If work W is required to stretch a spring a distance x from its unstretched length, what work (in... Problem 6.1E: You push your physics book 1.50 m along a horizontal table-top with a horizontal push of 2.40 N... Problem 6.2E: Using a cable with a tension of 1350 N, a tow truck pulls a car 5.00 km along a horizontal roadway.... Problem 6.3E: A factory worker pushes a 30.0-kg crate a distance of 4.5 m along a level floor at constant velocity... Problem 6.4E: Suppose the worker in Exercise 6.3 pushes downward at an angle of 30 below the horizontal. (a) What... Problem 6.5E: A 75.0-kg painter climbs a ladder that is 2.75 m long and leans against a vertical wall. The ladder... Problem 6.6E: Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.80 106 N. one 14... Problem 6.7E: Two blocks are connected by a very light string passing over a massless and frictionless pulley... Problem 6.8E: A loaded grocery cart is rolling across a parking lot in a strong wind. You apply a constant force... Problem 6.9E: A 0.800-kg ball is tied to the end of a string 1.60 m long and swung in a vertical circle. (a)... Problem 6.10E: A 12.0-kg package in a mail-sorting room slides 2.00 m down a chute that is inclined at 53.0 below... Problem 6.11E: A 128.0-N carton is pulled up a frictionless baggage ramp inclined at 30.0 above the horizontal by a... Problem 6.12E: A boxed 10.0-kg computer monitor is drugged by friction 5.50 m upward along a conveyor belt inclined... Problem 6.13E: A large crate sits on the floor of a warehouse. Paul and Bob apply constant horizontal forces to the... Problem 6.14E: You apply a constant force F=(68.0N)i+(36.0N)j to a 380-kg car as the car travels 48.0 m in a... Problem 6.15E: You are holding a briefcase by the handle, with your arm straight down by your side. Does the force... Problem 6.16E: When a book slides along a tabletop, the force of friction does negative work on it. Can friction... Problem 6.17E: Time yourself while running up a flight of steps, and compute the average rate at which you do work... Problem 6.18E: Fractured Physics. Many terms from physics are badly misused in everyday language. In both cases,... Problem 6.19E: Meteor Crater. About 50,000 years ago, a meteor crashed into the earth near present-day Flagstaff,... Problem 6.20E: A 4.80-kg watermelon is dropped from rest from the roof of an 18.0-m-tall building and feels no... Problem 6.21E: Use the work-energy theorem to solve each of these problems. You can use Newtons laws to check your... Problem 6.22E: Use the work-energy theorem to solve each of these problems. You can use Newtons laws to check your... Problem 6.23E: You are a member of an Alpine Rescue Team. You must project a box of supplies up an incline of... Problem 6.24E: You throw a 3.00-N rock vertically into the air from ground level. You observe that when it is 15.0... Problem 6.25E: A sled with mass 12.00 kg moves in a straight line on a friction less, horizontal surface. At one... Problem 6.26E: A mass m slides down a smooth inclined plane from an initial vertical height h, making an angle ... Problem 6.27E: A 12-pack of Omni-Cola (mass 4.30 kg) is initially at rest on a horizontal floor. It is then pushed... Problem 6.28E: A soccer ball with mass 0.420 kg is initially moving with speed 2.00 m/s. A soccer player kicks the... Problem 6.29E: A little red wagon with mass 7.00 kg moves in a straight line on a frictionless horizontal surface.... Problem 6.30E: A block of ice with mass 2.00 kg slides 1.35 m down an inclined plane that slopes downward at an... Problem 6.31E: Stopping Distance. A car is traveling on a level road with speed v0 at the instant when the brakes... Problem 6.32E: A 30.0-kg crate is initially moving with a velocity that has magnitude 3.90 m/s in a direction 37.0... Problem 6.33E: BIO Heart Repair. A surgeon is using material from a donated heart to repair a patients damaged... Problem 6.34E: To stretch a spring 3.00 cm from its unstretched length. 12.0 J of work must be done. (a) What is... Problem 6.35E: Three identical 8.50-kg masses are hung by three identical springs (Fig. E6.35). Each spring has a... Problem 6.36E: A child applies a force F parallel to the x-axis to a 10.0-kg sled moving on the frozen surface of a... Problem 6.37E: Suppose the sled in Exercise 6.36 is initially at rest at x = 0. Use the work-energy theorem to find... Problem 6.38E: A spring of force constant 300.0 N/m and unstretched length 0.240 m is stretched by two forces,... Problem 6.39E: A 6.0-kg box moving at 3.0 m/s on a horizontal, frictionless surface runs into a light spring of... Problem 6.40E: Leg Presses. As part of your daily workout, you lie on your back and push with your feet against a... Problem 6.41E: (a) In Example 6.7 (Section 6.3) it was calculated that with the air track turned off, the glider... Problem 6.42E: A 4.00-kg block of ice is placed against a horizontal spring that has force constant k = 200 N/m and... Problem 6.43E: A force F is applied to a 2.0-kg, radio-controlled model car parallel to the x-ax is as it moves... Problem 6.44E: Suppose the 2.0-kg model car in Exercise 6.43 is initially at rest at x = 0 and F is the net force... Problem 6.45E Problem 6.46E: Half or a Spring. (a) Suppose you cut a massless ideal spring in half. If the full spring had a... Problem 6.47E: A small glider is placed against a compressed spring at the bottom of an air track that slopes... Problem 6.48E: An ingenious bricklayer builds a device for shooting bricks up to the top of the wall where he is... Problem 6.49E: CALC A force in the +x-direction with magnitude F(x) = 18.0 N (0.530 N/m)x is applied to a 6.00-kg... Problem 6.50E: A crate on a motorized cart starts from rest and moves with a constant eastward acceleration of a... Problem 6.51E: How many joules of energy does a 100-watt light bulb use per hour? How fast would a 70-kg person... Problem 6.52E: BIO Should You Walk or Run? It is 5.0 km from your home to the physics lab. As part of your physical... Problem 6.53E: Magnetar. Oil December 27, 2004, astronomers observed the greatest flash of light ever recorded from... Problem 6.54E: A 20.0-kg rock is sliding on a rough, horizontal surface at 8.00 m/s and eventually stops due to... Problem 6.55E: A tandem (two-person) bicycle team must overcome a force of 165 N to maintain a speed of 9.00 m/s.... Problem 6.56E: When its 75-kW (100-hp) engine is generating full power, a small single-engine airplane with mass... Problem 6.57E: Working Like a Horse. Your job is to lift 30-kg crates a vertical distance of 0.90 m from the ground... Problem 6.58E: An elevator has mass 600 kg, not including passengers. The elevator is designed to ascend, at... Problem 6.59E: A ski tow operates on a 15.0 slope of length 300 m. The rope moves at 12.0 km/h and provides power... Problem 6.60E: You are applying a constant horizontal force F = (8.00 N) + (3.00 N) to a crate that is sliding on a... Problem 6.61E: BIO While hovering, a typical flying insect applies an average force equal to twice its weight... Problem 6.62P: CALC A balky cow is leaving the barn as you try harder and harder to push her back in. In... Problem 6.63P: A luggage handler pulls a 20.0-kg suitcase up a ramp inclined at 32.0 above the horizontal by a... Problem 6.64P: Chin-ups. While doing a chin-up, a man lifts his body 0.40 m. (a) How much work must the man do per... Problem 6.65P: Consider the blocks in Exercise 6.7 as they move 75.0 cm. Find the total work done on each one (a)... Problem 6.66P: A 5.00-kg package slides 2.80 m down a long ramp that is inclined at 24.0 below the horizontal. The... Problem 6.67P: CP BIO Whiplash Injuries. When a car is hit from behind, its passengers undergo sudden forward... Problem 6.68P: CALC A net force along the x-axis that has x-component Fx = 12.0 N + (0.300 N/m2)x2 is applied to a... Problem 6.69P: CALC Varying Coefficient of Friction. A box is sliding with a speed of 4.50 m/s on a horizontal... Problem 6.70P: CALC Consider a spring that does not obey Hookes law very faithfully. One end of the spring is... Problem 6.71P: CP A small block with Figure P6.71 a mass of 0.0600 kg is attached to a cord passing through a hole... Problem 6.72P: CALC Proton Bombardment. A proton with mass 1.67 1027 kg is propelled at an initial speed of 3.00 ... Problem 6.73P: You are asked to design spring bumpers for the walls of a parking garage. A freely rolling 1200-kg... Problem 6.74P: You and your bicycle have combined mass 80.0 kg. When you reach the base of a bridge, you are... Problem 6.75P: A 2.50-kg textbook is forced against a horizontal spring of negligible mass and force constant 250... Problem 6.76P: The spring of a spring gun has force constant k = 400 N/m and negligible mass. The spring is... Problem 6.77P: One end of a horizontal spring with force constant 130.0 N/m is attached to a vertical wall. A... Problem 6.78P: One end of a horizontal spring with force constant 76.0 N/m is attached to a vertical post. A... Problem 6.79P: A 5.00-kg block is moving at 0 = 6.00 m/s along a frictionless, horizontal surface toward a spring... Problem 6.80P: A physics professor is pushed up a ramp inclined up-ward at 30.0 above the horizontal as she sits in... Problem 6.81P: Consider the system shown in Fig. P6.81. The rope and pulley have negligible mass, and the pulley is... Problem 6.82P: Consider the system shown in Fig. P6.81. The rope and pulley have negligible mass, and the pulley is... Problem 6.83P: On an essentially frictionless, horizontal ice rink, a skater moving at 3.0 m/s encounters a rough... Problem 6.84P: BIO All birds, independent of their size, must maintain a power output of 10-25 watts per kilogram... Problem 6.85P: A pump is required to lift 800 kg of water (about 210 gallons) per minute from a well 14.0 m deep... Problem 6.86P: The Grand Coulee Dam is 1270 m long and 170 m high. The electrical power output from generators at... Problem 6.87P: A physics student spends part of her day walking between classes or for recreation, during which... Problem 6.88P: CALC An object has several forces acting on it. One of these forces is F = xy, a force in the... Problem 6.89P: BIO Power of the Human Heart. The human heart is a powerful and extremely reliable pump. Each day it... Problem 6.90P: DATA Figure P6.90 shows the results of measuring the force F exerted on both ends of a rubber band... Problem 6.91P: DATA In a physics lab experiment, one end of a horizontal spring that obeys Hookes law is attached... Problem 6.92P: DATA For a physics lab experiment, four classmates run up the stairs from the basement to the top... Problem 6.93CP: CALC A Spring with Mass. We usually ignore the kinetic energy of the moving coils of a spring, but... Problem 6.94CP: CALC An airplane in flight is subject to an air resistance force proportional to the square of its... Problem 6.95PP: BIO ENERGY OF LOCOMOTION. On flat ground, a 70-kg person requires about 300 W of metabolic power to... Problem 6.96PP: BIO ENERGY OF LOCOMOTION. On flat ground, a 70-kg person requires about 300 W of metabolic power to... Problem 6.97PP: BIO ENERGY OF LOCOMOTION. On flat ground, a 70-kg person requires about 300 W of metabolic power to... format_list_bulleted