Concept explainers
(III) A 4.0-kg block is stacked on top of a 12.0-kg block, which is accelerating along a horizontal table at a = 5.2 m/s2 (Fig. 5–40). Let μk = μs = μ. (a) What minimum coefficient of friction μ between the two blocks will prevent the 4.0-kg block from sliding off? (b) If μ is only half this minimum value, what is the acceleration of the 4.0-kg block with respect to the table, and (c) with respect to the 12.0-kg block? (d) What is the force that must be applied to the 12.0-kg block in (a) and in (b), assuming that the table is frictionless?
FIGURE 5–40 Problem 32.
Want to see the full answer?
Check out a sample textbook solutionChapter 5 Solutions
Modified Mastering Physics With Pearson Etext -- Standalone Access Card -- For Physics For Scientists & Engineers With Modern Physics (5th Edition)
Additional Science Textbook Solutions
Applied Physics (11th Edition)
College Physics: A Strategic Approach (4th Edition)
Cosmic Perspective Fundamentals
University Physics Volume 1
Essential University Physics (3rd Edition)
The Cosmic Perspective (8th Edition)
- A certain car traveling at 97 km/h can stop in 46 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(III) (a) Suppose the coefficient of kinetic friction between ma and the plane in Fig. 4-62 is µk = 0.15, and that mA = mB = 2.7 kg. As mB moves down, determine the magnitude of the acceleration of ma and mg, given 0 = 34°. (b) What smallest value of pk will keep the system from accelerating? [Ignore masses of the (frictionless) pulley and the cord.] mB FIGURE 4-62 Problem 67.arrow_forwardThree mountain climbers who are roped together in a line are ascending an icefield inclined at 31.0° to the horizontal (Fig. 4-69). The last climber slips, pulling the second climber off his feet. The first climber is able to hold them both. If each climber has a mass of 75 kg, calculate the ten- sion in each of the two sections of rope between the three climbers. Ignore friction between the ice and the fallen climbers. 31.0° FIGURE 4-69 Problem 83.arrow_forward
- A train locomotive is pulling two cars of the same mass behind it, Fig. 4–51. Determine the ratio of the tension in the coupling (think of it as a cord) between the locomotive and the first car (FT1), to that between the first car and the second car (FT2), for any nonzero acceleration of the train. You need to draw a FBD for each car.arrow_forward(b) The coefficient of static friction between Teflon and scram- bled eggs is about 0.04. What is the smallest angle from the horizontal that will cause the eggs to slide across the bottom of a Teflon-coated skillet?arrow_forward(II) A particular race car can cover a quarter-mile track (402m) in 6.40s starting from a standstill. Assuming the acceleration is constant, how many "g's" does the driver experience? If the combined mass of the driver and race car is 535 kg, what horizontal force must the road exert on the tires?arrow_forward
- A car starts rolling down a 1-in-4 hill (1-in-4 means that for each 4 m traveled along the sloping road, the elevation change is 1 m). How fast is it going when it reaches the bottom after traveling 55 m? (a) Ignore friction. (b) Assume an effective coefficient of friction equal to 0.10.arrow_forwardBodyA in Fig. 6-33 weighs 102 N, and body B weighs 32 N. The coefficients of friction between A and the incline are us =0.56 and uk=0.25. Angle 0 is 40°. Let the positive direction of an x axis be up the incline. In unit-vector notation, what is the acceleration of A if A is initially (a) at rest, (b) moving up the incline, and (c) moving down the incline Frictionless, massless pulleyarrow_forward(2) A force with magnitude 8.86 N pushes three boxes with masses m₁ = 1.30 kg, m2 = 3.20 kg, and m3 = 4.90 kg, as shown in the figure below. The surface the boxes are sliding on is so slippery that the surface can be considered to be frictionless. (a) Calculate the force that boxes 1 and 2 exert on each other and the force that boxes 2 and 3 exert on each other. [answer: F2-on-1 = F1-on-2 = 7.63 N; F3-on-2 = F2-on-3 = 4.62 N]. (b) To obtain the values of F1-on-2 and F3-on-2 in (a), you needed to assume that Newton's 3rd Law is valid. If you examine the FBD for m2, you should see that F1-on-2-F3-on-2= m2a. Verify the validity of Newton's 3rd Law by showing that the values of F1-on-2 - F3-on-2 and m2a are indeed equal. [answer: They are both equal to 3.0 N.] Fnet = ma F = 8.86 N 1.30 kg 3.20 kg t 4.90 kgarrow_forward
- (a) If half of the weight of a flatbed truck is supported by its two drive wheels, what is the maximum acceleration it can achieve on dry concrete where the coefficient of kinetic friction is 0.7 and the coefficient of static friction is 1..................m/s2(b) Will a metal cabinet lying on the wooden bed of the truck slip if it accelerates at this rate where the coefficient of kinetic friction is 0.3 and the coefficient of static friction is 0.55? No or Yes? (c) Answer both of these questions for the case that the truck has four-wheel drive, and the cabinet is wooden.maximum acceleration ................m/s2 Will it slip? Yes or No?arrow_forwardA 72-kg water skier is being accelerated by a ski boat on a flat (“glassy") lake. The coefficient of kinetic friction between the skier's skis and the water surface is Mk = 0.25 (Fig. 4–74). (a) What is the skier's acceleration if the rope pulling the skier behind the boat applies a horizontal ten- sion force of magnitude FT = 240 N to the skier (0 = 0°)? (b) What is the skier's horizontal acceleration if the rope pulling the skier exerts a force of FT = 240 N on the skier at an upward angle 0 = 12°? (c) Explain why the skier's acceleration in part (b) is greater than that in part (a). FT = 240 N Mk = 0.25 FIGURE 4-74 Problem 91.arrow_forwardThe 70.0-kg climber in Fig. 4-72 is supported in the “chimney" by the friction forces exerted on his shoes and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.80 and 0.60, respectively. What is the minimum normal force he must exert? Assume the walls are ver- tical and that the static friction forces are both at their maximum. Ignore his grip on the rope. FIGURE 4–72 Problem 89.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