Concept explainers
It’s possible for a determined group of people to pull an aircraft. Drag is negligible at low speeds, and the only force impeding motion is the rolling friction of the rubber tires on the concrete runway. In 2000, a team of 60 British police officers set a world record by pulling a Boeing 747, with a mass of 200,000 kg, a distance of 100 m in 53 s. The plane started at rest. Estimate the force with which each officer pulled on the plane, assuming constant pulling force and constant acceleration.
Want to see the full answer?
Check out a sample textbook solutionChapter 5 Solutions
College Physics: A Strategic Approach (4th Edition)
Additional Science Textbook Solutions
Human Biology: Concepts and Current Issues (8th Edition)
Human Anatomy & Physiology (2nd Edition)
Microbiology with Diseases by Body System (5th Edition)
Campbell Biology in Focus (2nd Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Organic Chemistry (8th Edition)
- A crate remains stationary after it has been placed on a ramp inclined at an angle with the horizontal. Which of the following statements must be true about the magnitude of the frictional force that acts on the crate? (a) It is larger than the weight of the crate. (b) It is at least equal to the weight of the crate. (c) It is equal to sn. (d) It is greater than the component of the gravitational force acting down the ramp. (e) It is equal to the component of the gravitational force acting down the ramp.arrow_forwardA sleigh is being pulled horizontally by a train of horses at a constant speed of 8.05 m/s. The magnitude of the normal force exerted by the snow-covered ground on the sleigh is 6.37 103 N. a. If the coefficient of kinetic friction between the sleigh and the ground is 0.23, what is the magnitude of the kinetic friction force experienced by the sleigh? b. If the only other horizontal force exerted on the sleigh is due to the horses pulling the sleigh, what must be the magnitude of this force?arrow_forwardIf a single constant force acts on an object that moves on a straight line, the objects velocity is a linear function of time. The equation v = vi + at gives its velocity v as a function of time, where a is its constant acceleration. What if velocity is instead a linear function of position? Assume that as a particular object moves through a resistive medium, its speed decreases as described by the equation v = vi kx, where k is a constant coefficient and x is the position of the object. Find the law describing the total force acting on this object.arrow_forward
- A large crate of mass m is placed on the flatbed of a truck but not tied down. As the truck accelerates forward with acceleration a, the crate remains at rest relative to the truck. What force causes the crate to accelerate? (a) the normal force (b) the gravitational force (c) the friction force (d) the ma force exerted by the crate (e) No force is required.arrow_forwardA ball is falling toward the ground. Which of the following statements are false? (a) The force that the ball exerts on Earth is equal in magnitude to the force that Earth exerts on the ball, (b) The ball undergoes the same acceleration as Earth. (c) The magnitude of the force the Earth exerts on the ball is greater than the magnitude of the force the ball exerts on the Earth.arrow_forwardAn object experiences no acceleration. Which of the following cannot be true for the object? (a) A single force acts on the object. (b) No forces act on the object. (c) Forces act on the object, but the forces cancel.arrow_forward
- In a tug-of-war game on one campus, 15 students pull on a rope at both ends in an effort to displace the central knot to one side or the other. Two students pull with force 196 N each to the light, four students pull with force 98 N each to the left, five students pull with force 62 N each to the left, three students pull with force 150 N each to the right, and one student pulls with force 250 N to the left. Assuming the positive direction to the tight, express the net pull on the knot in terms of the unit vector. How big is the net pull on the knot? In what direction?arrow_forwardA freight train has a mass of 1.5 x107 kg. If the locomotive can exert a constant pull of 7.5 x 105 N, how long does it take to increase the speed of the train from rest to 80 km/h?arrow_forwardTwo people are pushing a truck across a parking lot. The truck has a mass of about 2 × 103 kg. First, they take turns pushing. When Person A pushes the truck, the truck accelerates at a rate of 1 m/s2. When Person B pushes the truck, it accelerates at a rate of 2 m/s?. (a) Both people stand behind the truck and push in the same direction. What is the net force on the truck? At what rate will the truck accelerate? (b) Person A stands at the back of the truck and Person B stands at the front, and they push in opposite directions. What is the net force on the truck? At what rate will the truck accelerate? In what direction? For both (a) and (b), draw a picture indicating the forces applied by A and B as well as the motion of the truck.arrow_forward
- Just like Louis, Maria left a book on the roof of her car before driving away. The mass of the book was 731 grams. The coefficient of static friction between the book and the roof was 0.29. The coefficient of kinetic friction between the book and the roof was 0.24. Maria started her car and drove forward on level ground with an acceleration of 3.5 m/s?. As Maria was driving away with that acceleration, what was the magnitude of the force of friction (in newtons) between the book and the roof of the car?arrow_forwardSuppose you are pushing a box across the floor. The box has a mass of 50.0 kg, and there is a constant force of friction opposing your push of 75.0 N. As you push the box, it accelerates from rest to a speed of 2.50 m/s in 15.0 seconds. (a) What is the force of your push, in Newtons? (b) Suppose the box had a mass of 25.0 kg, and you pushed in with the same for that you found in part (a). What would the acceleration of the box be? How long would it take to reach a speed of 2.50 m/s, starting from rest?arrow_forwardA 645 kg car is being pushed along a flat parking lot at a constant speed of 1.78 m/s. The coefficient of friction between the road and the car is 0.26. What force is being used to push the car?arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill