Concept explainers
In the Soapbox Derby, young participants build non-motorized cars with very low-friction wheels. Cars race by rolling down a hill. The track at Akron’s Derby Downs, where the national championship is held, begins with a 55-ft-long section tilted 13º below horizontal.
a. What is the maximum possible acceleration of a car moving down this stretch of track?
b. If a car starts from rest and undergoes this acceleration for the full 55 ft, what is its final speed in m/s?
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
College Physics: A Strategic Approach (4th Edition)
Additional Science Textbook Solutions
Essential University Physics (3rd Edition)
Applied Physics (11th Edition)
Physics: Principles with Applications
College Physics
Sears And Zemansky's University Physics With Modern Physics
The Cosmic Perspective Fundamentals (2nd Edition)
- A car is driving along a circular track of diameter d = 0.75 km at a constant speed of v = 22 m/s.a. Write an expression for the magnitude of acceleration a of the car in terms of the given parameter. b. What is the magnitude, in meters per second squared, of the acceleration a of the car. c. Write an expression for the minimum coefficient of the friction μ between the car's tires and the road that is required in order to keep the car going in a circle in terms of the given parameters.arrow_forwardA. Suppose a planner is designing an airport for small airplanes. Such planes must reach a speed of 56 m/s before takeoff and can accelerate at 12.0 m/s2. What is the minimum length for the runway of this airport? B. How long does it take a car to travel 30.0 m if it accelerates from rest at a rate of 2.00 m/s2? C. A baseball pitcher throws a fastball with a speed of 30.0 m/s. Assume the acceleration is uniform and the distance through which the ball is accelerated is 3.50 m. What is the acceleration?arrow_forwardA kangaroo can jump over an object 2.7 m high. a. Calculate its vertical speed when it leaves the ground, in meters per second. b. How many seconds is it in the air?arrow_forward
- An object is thrown off the top of a building with velocity 32 m/s at an angle 34 degrees with respect to the horizontal. It takes 6.2 s for the object to land. a. How high is the building in meters? b. What is the horizontal distance that the object travels in meters?arrow_forwardOn an otherwise straight stretch of road near Moffat, Colorado, the road suddenly turns. This bend in the road is a segment of a circle with radius 110 m. Drivers are cautioned to slow down to 40 mph as they navigate the curve.a. If you heed the sign and slow to 40 mph, what will be your acceleration going around the curve at this constant speed? Give your answer in m/s2 and in units of g.b. At what speed would your acceleration be double that at the recommended speed?arrow_forwardScientists have investigated how quickly hoverflies start beating their wings when dropped both in complete darkness and in a lighted environment. Starting from rest, the insects were dropped from the top of a 40-cm-tall box. In the light, those flies that began flying 200 ms after being dropped avoided hitting the bottom of the box 80% of the time, while those in thedark avoided hitting only 22% of the time.a. How far would a fly have fallen in the 200 ms before it began to beat its wings?b. How long would it take for a fly to hit the bottom if it never began to fly?arrow_forward
- A rock is thrown down into a well with an initial downward speed of 3 m/s. the rock hits bottom 1.8 s later. a. How deep is the well? b. What is the rock’s speed as it hits the bottom?arrow_forwardThe Nardo ring is a circular test track for cars. It has a circumference of 12.5 km. cars travel around the track at a constant speed of 100 km/h. A car starts at the easternmost point of the ring and drives for 15 minutes at this speed. a. What distance, in km, does the car travel?arrow_forwardAn ambulance driver is rushing a patient to the hospital. While traveling at 72 km/h, she notices light at the upcoming intersections has turned amber. To reach the intersection before the light turns red, she must travel 50 m in 2 s. a. What minimum acceleration must the ambulance have to reach the intersection before the light turns red? b. What is the speed of the ambulance when it reaches the intersection?arrow_forward
- Shown is a graph of the motion of the blades of a blender that is starts empty and is initially turned off. Then the power is turned on at thehighest speed setting, some ice cubes are added, and the blades slow down. The blades are 3.0 cm long.a. When the blender is empty and running at high speed, how much time is required for a blade to turn by 90°?b. How many revolutions does a blade complete between 15 and 20 seconds?c. How fast is the tip of a blade moving when the blender is running empty?arrow_forwarda toy race car comepletes a lap around an 80 meter track in 15secs. a. what is the toy cars average velocity? b. what is the car's centripetal acceleration?arrow_forwardConsider the following descriptions of the vertical motion of an object subject only to the acceleration due to gravity. Begin with the acceleration equation a(t) = ν'(t) = -g, where g = 9.8 m/s2.a. Find the velocity of the object for all relevant times.b. Find the position of the object for all relevant times.c. Find the time when the object reaches its highest point. What is the height?d. Find the time when the object strikes the ground. A payload is dropped at an elevation of 400 m from a hot-air balloonthat is descending at a rate of 10 m/s.arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON