(I) A tower crane (Fig. 9–48a) must always be carefully balanced so that there is no net torque tending to tip it. A particular crane at a building site is about to lift a 2800-kg air-conditioning unit. The crane's dimensions are shown in Fig. 9-48b. (a) Where must the crane's 9500-kg counterweight be placed when the load is lifted from the ground? (The counterweight is usually moved auto- matically via sensors and motors to precisely compensate for the load.) (b) Determine the maximum load that can be lifted with this counterweight when it is placed at its full extent. Ignore the mass of the beam. (a) Counterweight M = 9500 kg +3.4 m- 7.7 m m = 2800 kg FIGURE 9-48 (b) Problem 3.

(I) A tower crane (Fig. 9–48a) must always be carefully balanced so that there is no net torque tending to tip it. A particular crane at a building site is about to lift a 2800-kg air-conditioning unit. The crane's dimensions are shown in Fig. 9-48b. (a) Where must the crane's 9500-kg counterweight be placed when the load is lifted from the ground? (The counterweight is usually moved auto- matically via sensors and motors to precisely compensate for the load.) (b) Determine the maximum load that can be lifted with this counterweight when it is placed at its full extent. Ignore the mass of the beam. (a) Counterweight M = 9500 kg +3.4 m- 7.7 m m = 2800 kg FIGURE 9-48 (b) Problem 3.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

A uniform beam is hinged at one end and held in a hori- zontal position by a cable, as shown in Fig. 9–42. The tension in the cable (a) must be at least half the weight of the beam, no matter what the angle of the cable. (b) could be less than half the beam's weight for some angles. (c) will be half the beam's weight for all angles. (d) will equal the beam's weight for all angles. FIGURE 9–42 MisConceptual Question 3: beam and cable.
As shown below, on Mars a beam of length L is leaning against a frictionless wall and is in static equilibrium. The center of mass of the beam is located 0.7L from the lower end of the beam and the wall is exerting a force of 56 N on the beam. 0.7 L 78° Determine the mass of the beam and the minimum coefficient of static friction between the floor and the beam. mass of the beam = Ms, min =
(5) We typically place our arms out for when we are crossing a narrow beam/rope. Is it because: (a) The larger leg muscles are unable to be used so we use the arms for leverage to bring our line of gravity back inside base of support; (b) To make our body area wider so the base of support is wider and line of gravity falls within it; (c) To make our body area wider so center of gravity naturally becomes lower and the body is more stable; (d) To utilize force summation to use larger muscles to bring us back into balance
FIGURE 9-67 W= 22 N Problem 27. 28. (III) You are on a pirate ship and being forced to walk the plank (Fig. 9-68). You are standing at the point marked C The plank is nailed onto the deck at point A, and rests on the support 0.75 m away from A. The center of mass of the uniform plank is located at point B. Your mass is 65 kg and the mass of the plank is 45 kg. What is the minimum down- ward force the nails must exert on the plank to hold it in place? A 3.0 m !0.75 m FIGURE 9-68 1.5 m B Problem 28. Fracture
A 2.0-m-high box with a 1.0-m-square base is moved across a rough floor as in Fig. 9–89. The uniform box weighs 250N and has a coefficient of static friction with the floor of 0.60. What minimum force must be 1.0 m exerted on the box to make it slide? What is the maximum height h above the floor that this force can be applied without tip- ping the box over? Note that as the box tips, the normal force CG 2.0 m FN and the friction force will act at the lowest corner. Fir FIGURE 9-89 Problem 74.
The uniform 19.0 kg beam below is 6.4 m long and is perfectly balanced about a point 1.4 m from the left end. What is the mass of the block? (Hint: when calculating the torque due to the weight of the beam, consider all of its mass to be located at its center of mass.)
A taho vendor carries a 1.5 m long light plank over his shoulder. At the ends of the plank are two buckets weighing 40 N and 60 N respectively. (a) Find the value of force F exerted by his shoulder. Neglect the weight of the plank. ( b) Where should he support the plank for it to be balanced horizontally
A wheelbarrow with w weight of 150N is used to lift a load with a weight of 900 N. The length from the wheel axle to the center of gravity (COG) of the load is 2 ft, and the distance to the (COG) of the wheelbarrow is 1.5 ft. The length from the wheel axle to the hands is 5 ft. The wheelbarrow is also tilted at an angle of 30 degrees with respect to the horizontal. Calculate the motive force required to hold the wheel barrow
As shown below, on Titan a 96 kg beam of length L is leaning against a frictionless wall and is in static equilibrium. The center of mass of the beam is located 0.8L from the lower end of the beam. 25° 0.8 L Determine the force the wall exerts on the beam and the minimum coefficient of static friction between the floor and the beam. force wall exerts on beam = μs, min =
In the figure, one end of a uniform beam of weight 100 N is hinged to a wall; the other end is supported by a wire that makes angles 8- 29 with both wall and beam. Find (a) the tension in the wire and the (b) horizontal anid (c) vertical components of the force of the hinge on the beam. Hinge (a) Number Units Units (b) Number Units (c) Nurmiber
A 12.0 m long uniform beam with a total weight of 840 N is clamped horizontally to the top of a wall with 4.0 m projecting over one side and 8.0 m projecting over the other side (see Fig. 6-33). Determine the total moment of force exerted by the beam at the wall.
3) To strengthen his arm and chest muscles, a 6-slug athlete who is 6'6" tall is doing push-ups as shown in the figure below. His centre of mass is 3'9" from the bottom of his feet, and the centres of his palms are one foot from the top of his head. Find the force that the floor exerts on each of his feet and on each hand, assuming that both feet exert the same force and both palms do likewise. Begin with a free-body diagram of the athlete. 6'6" K–1'-