A damping mechanism for closing a door allows it to close on its own, as shown in the figure. The shock consists of a spring to return attached to an oil-filled damping piston. When the spring pulls the piston to the right, the teeth of the piston bar engage in a sprocket, which rotates and causes the door to close. Should the system be sub-meame, critically cushioned or over-cushioned for best performance (where the door closes quickly without hitting the frame)? Explain your answer.

Part D - Present the equations of motion for the system, including the rate of change of deflection. Make sure to simplify your equations as much as possible.

A four-cylinder automobile engine must be supported on three shock mounts,as shown in the picture. The engine block assembly weighs500 lbs. If the unbalanced force produced by the engine is given by200 sin 100 t lb, design three shock mounts (each stiffness k andviscous damping constant c) such that the vibration amplitudemaximum 0.1 in

Q3/A polyamide A-3 flat belt 6 in wide is used to transmit 15 hp under light shock conditions where Ks = 1.25, and a factor of safety equal to or greater than 1.1 is appropriate. The pulley rotational axes are parallel and in the horizontal plane. The shafts are 8 ft apart. The 6-in driving pulley rotates at 1750 rev/min in such a way that the loose side is on top. The driven pulley is 18 in in diameter. See Fig. 17-10. The factor of safety is for unquantifiable exigencies. 1750 rpm 6 in -96 in 18 in (a) Find the torque capacity that would put the drive as built at the point of slip, as well as the initial tension Fi. (b) Find the belt width b that exhibits nfs = nd = 1.1. (c) For part b find the corresponding Fla, Fc, Fi, F2, power, and nfs. (d) What have you learned?

The external and internal diameter of a single plate clutch are 125 mm and 100 mm, respectively. It is used to transmit power at limited (maximum) axial pressure of 0.2 MPa. Which of the following is the axial force exerted by the springs? Assume uniform wear conditions. Choices:  790N1960N 440N 980N

Q1: Determine the equivalent spring constant of the system shown in Fig. 1 k₁ k3 0000 mão S k₂ 0000 ks 0000-0000 eeeeeeee K₁ Fig.1

mechanical principles Explain the natural frequency of vibration in a mass-spring system.

Question 2 A reciprocating engine is installed on the fifth floor of a new building to provide ventilation services, which can be modelled as a rigid rectangular plate resting on four elastic columns. The total mass of the engine and floor is 1000 kg. At the rated speed of the engine, which is 750 rev/min, the engineers experienced large vibrations of the floor. It has been decided to reduce these vibrations by suspending a spring-mass system at the bottom surface of the floor as the absorber. (a) If the stiffness of the absorber is 980 kN/m, find the mass of the dynamic absorber to be attached to the floor. (b) Find the values of the absorber mass and absorber stiffness in order to have the natural frequencies of the combined system at least 25% away from the forcing frequency. Verify your answer with a calculation.

A helical compression spring is required to provide a minimum force of 150 lb at installation and have a working deflection of 1 in. The spring rate is 75 lb/in. The coil must fit in a 2.1-in-dia hole with 0.1 in total clearance. Use 0.25-in diameter unpeened music wire and squared/ground ends. Use a 15% clash allowance, shear modulus G = 11.5 Mpsi, and weight density γ = 0.285 lb/in3. Assume Sys = 0.6Sut. Part A Find the shear stress at the initial deflection. Express your answer in pounds per square inch to three significant figures.         τiτi =       Part B Find the mean stress. Express your answer in pounds per square inch to three significant figures.     Part C Find the alternating stress in the coil. Express your answer in pounds per square inch to three significant figures.     Part D Find the fatigue safety factor for infinite life in shear. Express your answer using three significant figures.…

As illustrated in the figure below, the bedplate of an experimental diesel engine is supported on four springs to isolate the vibrations from the test frame. The effective weight of the diesel engine and bedplate is 43kg and the stiffness of each of the four springs is 250 kN/m. Using a simplified approach - by applying Newton's Second Law assuming a single degree of freedom system and ignoring damping - what rotational engine speed is best avoided? Bedplate Test engine Supporting springs Figure: Sketch of a test engine mounting arrangement Give your answer in rad/s to 1 decimal place.