The cable cars in San Francisco are pulled along their tracks by an underground steel cable that moves along at 9.5 mph. The cable is driven by large motors at a central power station and extends, via an intricate pulley arrangement, for several miles beneath the city streets. The length of a cable stretches by up to 100 ft during its lifetime. To keep the tension FIGURE EX7.21 constant, the cable passes around a 1.5-m-diameter "tensioning pulley" that rolls back and forth on rails, as shown in FIGURE EX7.21. A 2000 kg block is attached to the tensioning pulley's cart, via a rope and pulley, and is suspended in a deep hole. What is the tension in the cable car's cable?
FIGURE EX7.21
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics, Books a la Carte Edition; Student Workbook for Physics for Scientists ... eText -- ValuePack Access Card (4th Edition)
- A 1.50 kg sphere is connected to one end of massless, 2.0 m long string. The other end of the string is fixed to the ceiling. The sphere is raised 0.300 m above its lowest point and then given a push so it has an initial speed is 5.00 m/s. When the sphere is at its lowest point, what is the tension in the string? 1.50 kg 0.300 m 5.00 m/sarrow_forwardIn a crash test, a car is driven into a solid wall at a speed of 35 mph. the car's acceleration as it crashes into the wall. What is the maximum force experienced by the 1530kg car?arrow_forwardDetermine the magnitude of the y-component of the reaction force at pin A (in kN). The beam AB is a standard 0.5 m I-beam with a mass of 95 kg per meter of length. 14 l A 0.25 m 0.5 m 0.12 m 5 m 25° 1.5 m 10 kN Barrow_forward
- A window washer is standing on a scaffold supported by a vertical rope at each end. The scaffold weighs 192 N and is 2.9 m long. What is the tension in each rope when the 692-N worker stands 1.14 m from one end? smaller tension larger tension Narrow_forwardThe tension is growing!Context At your summer job, your supervisor wants to test your physics skills. A new winch (a cable driven by a motor) is to be used to hoist loads up an inclined ramp. Your supervisor is worried about the packages arriving too quickly at the top of the ramp. Constraints The inclined ramp is made up of small cylinders that are free to rotate: there is no friction between the ramp and the load.The angle theta of the ramp from the horizontal is known.The winch cable exerts a known force.The cable is oriented at an angle a from the horizontal.The charge, initially immobile, has a known mass.The length of the ramp is known. Schematization Draw a diagram of the object that interests us. Draw your x and y axes. Draw and name each force experienced by the object that interests us. Modelization Build a model to calculate the final speed of the load as it arrives at the top of the ramp, given the known parameters. Then test your model with the following values: Ramp…arrow_forwardA 10-meter boom with a mass of 30 kilograms is held by a steel cable 6 meters from its left end. What is the tension on the steel cable? 35⁰ 6 m 599 N 428 N none of the choices -299 N 299 Narrow_forward
- A 1500-N crate is to be held in place on a ramp that rises at 30.0° above the horizontal (see figure). The massless rope attached to the crate makes a 22.0° angle above the surface of the ramp. The coefficients of friction between the crate and the surface of the ramp are uk = 0.450 and us = 0.650. The pulley has no appreciable mass or friction. What is the MAXIMUM weight w that can be used to hold this crate stationary on the ramp? %3D W= ? Crate 22.0° Ramp 30.00arrow_forwardA 200 g hockey puck is launched up a metal ramp that is inclined at a 30° angle. The coefficients of static and kinetic friction between the hockey puck and the metal ramp are us 0.40 and uk = 0.30, respectively. The puck's initial speed is 4.9 m/s. What speed does it have when it slides back down to its starting point? 2.8 m/s 4.9 m/s 4.2 m/s 3.5 m/sarrow_forwardA heavy crate is suspended from two ropes as it is lowered from a high shelf to the floor at a constant speed. One of the ropes makes an angle of 28.2 degrees with respect to the vertical and has a tension of 950 N, while the other makes an angle of 33.7 with respect to the vertical. What is the crate's mass in kg?arrow_forward
- A 80.0 kg mail bag hangs by a vertical rope 3.5 m long. A postal worker then displaces the bag to a position 2.4 m sideways from its original position, always keeping the rope taut.arrow_forwardA uniform 25kg bar, 6.0m long is suspended by a cord shown. What is the tension in the cord? wall cord 27° -6.0 m- 3.7 x 102 N 02.7 x 10² N 1.2 x 10² N 5.4 x 10² Narrow_forwardSome salvage divers are raising a rectangular box of treasure measuring1m × 1.3m × 1.9m from the bottom of the sea. They are using a cable which can handle a maximum force of 10 000 N without breaking. They raise the treasure from the bottom of the ocean at a constant speed. All goes well while the treasure is rising through the water but much to the despair of the salvors as soon as the treasure is clear of the water the cable breaks, dropping the treasure back into the briny deep. What are the maximum and minimum possible weights of the lost treasure?arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning