1. Determine the force P required to maintain the 200-kg engine in the position for which q = 30o. The diameter of the pulley at B is negligible.

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2. The collar A of mass m may slide freely on the horizontal frictionless rod. The spring attached to the collar has a stiffness of 10 N/cm and it is undeformed when the collar is directly below support B. Determine the magnitude of the force P required to maintain equilibrium.

9 cm

12 cm

B

A P

m

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3. A scale is constructed using the 10 kg mass A, the 2 kg pan P and the pulley and cord arrangement. Cord BCA is 2 m long. If s = 0.75 m, determine the mass D in the pan. Neglect the size of the pulley.

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4. The hoist shown is used to position heavy workpieces in a lathe. If the cable between pulleys A and B can support a maximum force of 1.2 kN, all other cables can support a maximum force of 2.2 kN, and bar CE can support a maximum comressive force of 2.6 kN, determine the largest weight W that may be lifted.

Note that bar CE is a two force member which can support a force along its longitudinal axis.

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5. The pipe is held in place by the vice. If the bolt exerts a force of 250 N on the pipe in the direction shown, determine the forces FA and FB that the smooth contacts at A and B exert on the pipe.

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6. Each cord can sustain a maximum pressure of 2000 N. Determine the largest weight of the sack that can be supported. Also determine q of cord DC for equilibrium.

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7. Determine the mass of each of the two cylinders if they cause a sag of s = 0.5 m when supported from the rings at A and B. Note that s = 0 when the cylinders are removed.

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2 m

A

B

C

y

10 m

8. The pail and its contents have mass of 60 kg. If cable BAC is 15 m long, determine the distance y of the pulley for equilibrium. Neglect the mass of the pulley. Also find the tension in the cable.

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9. A small peg P rests on a spring that is contained inside the smooth pipe. When the spring is compressed so that s = 0.15 m, the spring exerts anupward force of 60 N on the peg. Determine the point of attachmentA (x, y, 0) of cord PA so that the tension in cords PB and PC equals 30 N and 50 N, respectively.

B

A

x

0.3 m

y x

z

y

s

C

P

0.2 m 0.4 m

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10. Straight bar AB is fixed in space. Spring CD has a stiffness of 3 N/mm and its unstretched length is 200 mm. If there is no friction between collar C and bar AB, determine the weight W of the collar that produces the equilibrium condition shown and the reaction between the collar and bar AB.

Homework 2

x

y

z

11. Determine the tensions in cables AB, AC, and AD.

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12. Determine the stretch in each of the two springs required to hold the 20 kg crate in the equilibrium position shown. Each spring has an unstretched length of 2 m and a stiffness of k = 300 N/m.

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13. Determine the force in each cable used to lift the 9.50 Mg surge arrester at constant velocity.

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14. If the maximum allowable tension in cables AB and AC is 2000 N, determine the maximum height z to which the 800 N crate can be lifted. What horizontal force must be applied?

W=800 N y x

1.5 m

2 m

2 m z

A

B

C

z 3 m

F

F

Homework 2