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A car is stuck in the mud. A tow truck pulls on the car with the arrangement shown in Fig. P4.32. The tow cable is under a tension of 2 500 N and pulls downward and to the left on the pin at its upper end. The light pin is held in equilibrium by forces exerted by the two bars A and B. Each bar is a strut; that is, each is a bar whose weight is small compared to the forces it exerts and which exerts forces only through hinge pins at its ends. Each strut exerts a force directed parallel to its length. Determine the force of tension or compression in each strut. Proceed as follows. Make a guess as to which way (pushing or pulling) each force acts on the top pin. Draw a free-body diagram of the pin. Use the condition for equilibrium of the pin to translate the free-body diagram into equations. From the equations calculate the forces exerted by struts A and B. If you obtain a positive answer, you correctly guessed the direction of the force. A negative answer means that the direction should be reversed, but the absolute value correctly gives the magnitude of the force. If a strut pulls on a pin, it is in tension. If it pushes, the strut is in compression. Identify whether each strut is in tension or in compression.
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Chapter 4 Solutions
Principles of Physics: A Calculus-Based Text
- Two blocks, each of mass m = 3.50 kg, are hung from the ceiling of an elevator as in Figure P4.33. (a) If the elevator moves with an upward acceleration a of magnitude 1.60 m/s2, find the tensions T1 and T2 in the upper and lower strings. (b) If the strings can withstand a maximum tension of 85.0 N, what maximum acceleration can the elevator have before a string breaks? Figure P4.33 Problems 33 and 34.arrow_forwardA bag of cement weighing 325 N hangs in equilibrium from three wires as suggested in Figure P4.23. Two of the wires make angles 1 = 60.0 and 2 = 40.0 with the horizontal. Assuming the system is in equilibrium, find the tensions T1, T2, and T3 in the wires. Figure P4.23 Problems 23 and 24.arrow_forwardwhat is the magnitude of the acceleration of a skydiver who is currently falling at 3/8 his eventual terminal speed?arrow_forward
- A person weighing 0.70 kN rides in an elevator that has an upward acceleration of 1.5 m/s 2. What is the magnitude of the force of the elevator floor on the person?arrow_forwardA skier with a mass of 60 kg is sliding down a snowy slope, the slope with an angle of 30 degrees above the horizontal as shown in the figure. Find the acceleration for the skier if friction is known to be 45.0 N. Assuming no air resistance and g=10m/s^2. a) 10 m/s^2 b) 0.75 m/s^2 c) 4.25 m/s^2 d) 1.33 m/s^2arrow_forwardIn the figure, a slab of mass m1 = 40 kg rests on a frictionless floor, and a block of mass m2 = 10 kg rests on top of the slab. Between block and slab, the coefficient of static friction is 0.60, and the coefficient of kinetic friction is 0.40. A horizontal force F→ of magnitude 104 N begins to pull directly on the block, as shown. In unit-vector notation, what are the resulting accelerations of (a) the block and (b) the slab?arrow_forward
- What is the resultant of two forces , acting on the same point and plain: F1= 50 N at 480 north of east and F2 = 80 N at 480 north of west.? 300.4 N 98.67 N 66.45 N 101.9 Narrow_forwardAn antelopebis being pulled by two forces whose vector-component expressions are: F1: -3.3Ni + 4.5 Nj + -2.7Nk F2: -1Ni + 0.2 Nj + 3.4 Nk What is the angle (in degrees) between these two vectors?arrow_forwardIn the figure, block 1 of mass m1 = 1.9 kg and block 2 of mass m2 = 1.4 kg are connected by a string of negligible mass. Block 2 is pushed by force F→ of magnitude 23 N and angle θ = 33°. The coefficient of kinetic friction between each block and the horizontal surface is 0.16. What is the tension in the string?arrow_forward
- In a movie, a stuntman places himself on the vertical front of a truck as the truck accelerates. The coefficient of static friction between the stuntman and the truck is 0.370. The stuntman is not standing on anything but can “stick” to the front of the truck as long as the truck continues to accelerate. What minimum forward acceleration will keep the stuntman on the front of the truck?arrow_forwardA block with mass m1 = 8.7 kg is on an incline with an angle θ = 37° with respect to the horizontal. The coefficients of friction are: μk = 0.36 and μs = 0.396. Another block with mass m2 = 15.5 kg is attached to the first block. The new block is made of a different material and has a greater coefficient of static friction. What minimum value for the coefficient of static friction is needed between the new block and the plane to keep the system from accelerating?arrow_forwardCauchy is trying to push a cart with a force of 75N at an angle of 34 degrees, but the ground is sloped in a way that causes the cart to naturally slide with a force of 20N at an angle of 274 degrees. What direction and with what force should Cauchy actually push the cart?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning