An object of mass m = 5.00 kg, attached to a spring scale, rests on a frictionless, horizontal surface as shown in Figure P6.14. The spring scale, attached to the front end of a boxcar, reads zero when the car is at rest. (a) Determine the acceleration of the car if the spring scale has a constant reading of 18.0 N when the car is in motion. (b) What constant reading will the spring scale show if the car moves with constant velocity? Describe the forces on the object as observed (c) by someone in the car and (d) by someone at rest outside the car.
Figure P6.14
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
Physics for Scientists and Engineers with Modern Physics
Additional Science Textbook Solutions
Fundamentals of Physics Extended
Chemistry: Structure and Properties (2nd Edition)
Campbell Biology (11th Edition)
Organic Chemistry (8th Edition)
Introductory Chemistry (6th Edition)
- You have landed on an unknown planet, Newtonia, and want to know what objects weigh there. When you push a certain tool, starting from rest, on a frictionless horizontal surface with a 12.0 N force, the tool moves 16.0 m in the first 2.00 s. You next observe that if you release this tool from rest at 10.0 m above the ground, it takes 2.58 s to reach the ground. What does the tool weigh on Newtonia, and what does it weigh on earth?arrow_forwardA box rests on top of a flat bed truck. The box has a mass of m = 20 kg. The coefficient of static friction between the box and truck is u, = 0.81 and the coefficient of kinetic friction between the box and truck is Hk = 0.62. 1) The truck accelerates from rest to v; = 16 m/s in t = 12 s (which is slow enough that the box will not slide). What is the acceleration of the box? m/s Submit You currently have O submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question. 2) In the previous situation, what is the frictional force the truck exerts on the box? N Submit You currently have 0 submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question. 3) What is the maximum acceleration the truck can have before the box begins to slide? m/s Submit You currently have O submissions for this question. Only 5 submission are allowed. You can make 5 more submissions for this question. 4) Now the…arrow_forwardA 3.00 kg box that is several hundred meters above theearth’s surface is suspended from the end of a short vertical rope of negligiblemass. A time-dependent upward force is applied to the upper endof the rope and results in a tension in the rope of T1t2 = (36.0 N/s)t.The box is at rest at t = 0. The only forces on the box are the tension inthe rope and gravity. What is the maximum distance that the box descends below its initial position?arrow_forward
- In the figure provided, a 0.670 kg box sits on top of a 1.83 kg box. A rope connects the smaller box to a wall while another rope is pulling the larger box to the right with a tension force of 31.6 N. If the coefficient of kinetic friction at both the lower and upper surfaces of the larger box is μk = 0.570, what is the acceleration of the larger box? Assume the ropes are massless.arrow_forwardA firefighter of mass 79 kg slides down a vertical pole with an acceleration of 4 m/s2.The acceleration of gravity is 10 m/s2.What is the friction force that acts on him?Answer in units of N.arrow_forwardA block of mass 1.90 kg is accelerated across a rough surface by a light cord passing over a small pulley as shown in the figure below. The tension T in the cord is maintained at 10.0 N, and the pulley is 0.130 m above the top of the block. The coefficient of kinetic friction is 0.370. M T (a) Determine the acceleration of the block when x = .400 m. m/s² (b) Describe the general behavior of the acceleration as the block slides from a location where x is large to x = 0. increasing, then decreasing no change O decreasing, then increasing a = (c) Find the maximum value of the acceleration and the position x for which it occurs. X = m m/s² (d) Find the largest value of x for which the acceleration is zero. marrow_forward
- A car has a mass of 1750 kg. If the driver applies the brakes while on a gravel road, the maximum friction force that the tires can provide without skidding is about 6500 N. If the car is moving at 22 m/s, what is the shortest distance in which the car can stop safely?arrow_forwardA fisherman has caught a very large, 5.0 kg fish from a dock that is 2.0 m above the water. He is using a lightweight fishing line that will break under a tension of 60N or more. He is eager to get the fish to the dock in the shortest possible time. If the fish is at rest at the water's surface, what's the least amount of time in which the fisherman can raise the fish to the dock without losing it? Express your answer with the appropriate units.arrow_forwardA 45 kg box hangs from a rope. What is the tension in the rope if:(a) the box is at rest?(b) the box is rising with a constant velocity of 4.0 m/s?(c) the box is rising and speeding up at 4.5 m/s2?arrow_forward
- A cable lowers a 1050 kg elevator so that the elevator's speed increases from zero to 4.0 m/s in a vertical distance of 5.9 m. what is the force that the cable exerts on the elevator while lowering it? (Assume that the system is the elevator man)arrow_forwardA 35.0-kg child swings in a swing supported by two chains, each 2.90 m long. The tension in each chain at the lowest point is 426 N. (a) Find the child's speed at the lowest point.Answer in m/s(b) Find the force exerted by the seat on the child at the lowest point. (Ignore the mass of the seat.)Answer in N (upward)arrow_forwardMary applies a force of 80 N to push a box with an acceleration of 0.40 m/s². When she increases the pushing force to 86 N, the box's acceleration changes to 0.63 m/s². There is a constant friction force present between the floor and the box. (a) What is the mass of the box in kilograms? 200 X Consider applying Newton's Second Law to each of the pushing forces. kg (b) What is the coefficient of kinetic friction between the floor and the box? -0.020 X What is the relation between friction force and normal force? Did you apply Newton's Second Law to motion in the vertical direction?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning