Concept explainers
You’ve always wondered about the acceleration of the elevators in the 101-story-tall Empire State Building. One day, while visiting New York, you take your bathroom scale into the elevator and stand on it. The scale reads 150 lb as the door closes. The reading varies between 120 lb and 170 lb as the elevator travels 101 floors.
a. What is the magnitude of the acceleration as the elevator starts upward?
b. What is the magnitude of the acceleration as the elevator brakes to a stop?
Trending nowThis is a popular solution!
Chapter 5 Solutions
COLL PHYSICS UPDATE V2&S/WRKBK&MOD MST/
Additional Science Textbook Solutions
Introduction to Electrodynamics
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
University Physics with Modern Physics (14th Edition)
Physics: Principles with Applications
Applied Physics (11th Edition)
The Cosmic Perspective (8th Edition)
- When Julia Child would cook an omelet, she would rapidly jostle the pan back and forth (Fig. P5.4). The egg would slosh back and forth in the pan as it cooked. Use Newtons laws to explain the eggs motion. FIGURE P5.4arrow_forwardA ball hanging from a light string or rod can be used as an accelerometer (a device that measures acceleration) as shown in Figure P5.18. What force causes the deflection of the ball? Is the cart in the lower part of the photo an inertial reference frame? How can the balls deflection be used to find the carts acceleration? In which direction is the cart accelerating? Explain your answers.arrow_forwardA car of mass 875 kg is traveling 30.0 m/s when the driver applies the brakes, which lock the wheels. The car skids for 5.60 s in the positive x-direction before coming to rest. (a) What is the cars acceleration? (b) What magnitude force acted on the car during this time? (c) How far did the car travel?arrow_forward
- Two blocks, each of mass m, are hung from the ceiling of an elevator as in Figure P4.33. The elevator has an upward acceleration a. The strings have negligible mass. (a) Find the tensions T1 and T2 in the upper and lower strings in terms of m, a, and g. (b) Compare the two tensions and determine which string would break first if a is made sufficiently large. (c) What are the tensions if the cable supporting the elevator breaks? Figure P4.33 Problems 33 and 34.arrow_forwardReview. A block of mass m = 2.00 kg is released from rest at h = 0.500 m above the surface of a table, at the top of a = 30.0 incline as shown in Figure P4.53. The frictionless incline is fixed on a table of height H = 2.00 m. (a) Determine the acceleration of the block as it slides down the incline. (b) What is the velocity of the block as it leaves the incline? (c) How far from the table will the block hit the floor? (d) What time interval elapses between when the block is released and when it hits the floor? (e) Does the mass of the block affect any of the above calculations? Figure P4.53 Problems 53 and 59arrow_forwardA 200 kg man rides in an elevator while standing on a scale. As the elevator rises with a constant acceleration of 6m/s2, what is the reading of the scale? b) As the elevator lowers itself with a constant acceleration of 6m/s2, what is the reading of the scale? c) As the elevator rises with a constant velocity of 2m/s, what is the reading of the scale? d) A 200 kg man rides an elevator while standing on a scale. What is the weight of the man?arrow_forward
- A hockey puck (mass = 3 kg) leaves the players stick with a speed of 20 m/s and slides on the ice for 80 meters before coming to rest.a) What is the magnitude of the acceleration on the puck? m/s2 b) What is the magnitude of the friction force exerted on the puck due to the ice? N c) What is the normal force on the puck? N d) What is the friction coefficient between the puck and the ice? (unitless)arrow_forwardA 60 kg person stands on a scale in an elevator. How many Newtons does the scale read: a) when the elevator is ascending with an acceleration of 1 m/s2? b) when the elevator is descending with an acceleration of 1 m/s2? c) when the elevator is ascending at a constant speed of 3 m/s?arrow_forward1. A (5 kg) object is thrown vertically into the air with an initial speed of (12 m/s).(a) What is the length of time between the object being thrown and it hitting the ground?(b) What is the maximum height that the object reaches?(c) What is the weight of the object?(d) Repeat part (a) if the local acceleration due to gravity is (15 m/s2).(e) Repeat part (b) if the local acceleration due to gravity is (15 m/s2).arrow_forward
- A student’s backpack, full of textbooks, is hung from a spring scale attached to the ceiling of an elevator. When the elevator is accelerating downward at 3.8 m/s2 , the scale reads 60 N. (a) What is the mass of the backpack? (b) What does the scale read if the elevator moves upward while speeding up at a rate 3.8 m/s2 ? (c) What does the scale read if the elevator moves upward at constant velocity? (d) If the elevator had no brakes and the cable supporting it were to break loose so that the elevator could fall freely, what would the spring scale read?arrow_forwardResearchers often use force plates to measure the forces that people exert against the floor during movement. A force plate works like a bathroom scale, but it keeps a record of how the reading changes with time. Shown is the data from a force plate as a woman jumps straight up and then lands.a. What was the vertical component of her acceleration during push-off?b. What was the vertical component of her acceleration while in the air?c. What was the vertical component of her acceleration during the landing?d. What was her speed as her feet left the force plate?e. How high did she jump?arrow_forwardA dragster and driver together have mass 893.6 kg. The dragster, starting from rest, attains a speed of 26.3 m/s in 0.57 s . a) Find the average acceleration of the dragster during this time interval in m/s2. b)What is the size of the average force on the dragster during this time interval in N? c)Assume the driver has a mass of 75.7 kg . What horizontal force does the seat exert on the driver in N?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning