Machine Elements 1 Midterm Exam PDF

## Machine elements 1 ### Midterm exam **Name:** ANSWER KED **Score:** **Section:** **Date:** 1. The study of motion in mechanisms without reference to the forces that cause the motion is called **KINEMATICS** 2. A rigid body having two or more pairing elements which connect it to other bodies fo...

## Machine elements 1 ### Midterm exam **Name:** ANSWER KED **Score:** **Section:** **Date:** 1. The study of motion in mechanisms without reference to the forces that cause the motion is called **KINEMATICS** 2. A rigid body having two or more pairing elements which connect it to other bodies for the purpose of transmitting force or motion is known as a **LINK** 3. A **JOINT/KINEMATIC PAIR** connection between links that allows some motion between the connected links. 4. A kinematic pair with surface contact (when deformation is neglected) is known as a **LOWER PAIR** 5. The number of independent inputs needed to precisely position all links of a mechanism relative to the ground is known as the **DEGREES OF FREEDOM / MOBILITY** 6. A four-bar linkage in which the shortest link can fully rotate is called a **GRASHOF MECHANISM**. 7. The angle between the coupler and the follower in a four-bar linkage is referred to as the **TRANSMISSION ANGLE** 8. In a slider-crank mechanism, the positions where the crank and connecting rod are collinear are known as the **LIMITING POSITIONS / DEAD CENTERS** 9. A mechanism designed to produce a slow working stroke and a quick return stroke is called a **QUICK RETURN MECHANISM** 10. The combination of kinematics and kinetics, which studies the motion of bodies under the action of forces, is called **DYNAMICS** 11. A joint that allows only relative rotation between two links is known as a **REVOLUTE / PIN JOINT** 12. A joint that allows only relative sliding motion between two links is known as a **PRISMATIC JOINT** 13. A kinematic pair that permits both rotation and sliding, independently, is called a **CYLINDRIC PAIR** 14. A **MECHANISM** is a kinematic chain in which one link is fixed. 15. The fixed or stationary link in a mechanism is called the **FRAME** 16. A combination of two revolute joints that allows two angular rotations is called a **UNIVERSAL JOINT** 17. A linkage where each link is connected to at least two other links is called a **CLOSED LOOP KINEMATIC CHAIN** 18. A linkage with one or more links connected to only one other link is called an **OPEN LOOP KINEMATIC CHAIN** 19. Machines or linkages designed to simulate human arm and hand motions are called **MANIPULATORS** 20. A connection between two links that allows only relative rotation is known as a **REVOLUTE / PIN JOINT** 21. A kinematic pair that permits both angular rotation and independent sliding motion is called a **CYLINDRIC PAIR** 22. A **GLOBULAR / SPHERICAL** joint allows rotation about three axes. 23. A combination of two revolute joints that allows two angular rotations is called a **UNIVERSAL JOINT** 24. A **GEAR / CAM** is a higher pair joint with rolling and sliding contact 25. The idealization that assumes machine components do not deflect under load is known as a **RIGID LINK** 26. A combination of links and joints that provides a controlled output motion in response to an input motion is called a **KINEMATIC CHAIN / LINKAGE** 27. A linkage in which the motion of all links occurs in parallel planes is known as a **PLANAR LINKAGE** 28. The time it takes for a mechanism to return to its original configuration after completing all its motions is called the **PERIOD** 29. A combination of bodies connected by joints, but designed to support loads rather than transmit motion, is called a **STRUCTURE** 30. A Grashof four-bar mechanism where the shortest link is the frame, and both cranks fully rotate, is called a **DRAG-LINK MECHANISM** 31. A Grashof mechanism where no link can fully rotate is called a **DOUBLE ROCKER MECHANISM** 32. A non-Grashof four-bar linkage where no link can fully rotate is called a **TRIPLE ROCKER MECHANISM** 33. The condition Lmax + Lmin <= La + Lb for a four-bar linkage is known as **GRASHOF LAW / GRASHOF CRITERION** 34. A simple machine that consists of a rigid beam pivoted about a fixed point is called a **LEVER** 35. The study of forces and torques on systems at rest or in equilibrium is called **STATICS** **36. Determine the total number of links.** - appliance: **L-4** - self: **L-4** - Spring is not a rigid body - **J-4** **37. Determine the total number of joints.** - **L-8** - **J-10** **38. Determine the total number of links.** - Window - (sill fixed) **L-6** - **J-6** **39. Determine the total number of joints.** - upper handle **L-4** - cutting - ends - (lower handle fixed) **J-4** **40. Determine the total number of links.** - **L-4** - **J-4** **41. Determine the total number of joints.** - **J-4** - **L-4** **42. Determine the total number of links.** - **L-10** - **J-12** **43. Determine the total number of joints.** - **L-9** - **J-11** **44. For the swing-out window in Figure P3.10, determine the length, s, of the two identical support links when x = 850 mm, d = 500 mm, and β = 35°.** - **s = 175 mm** **45. Determine the vertical height of the basket in Figure P3.18 when a = 24 in., b = 36 in., c = 30 in., d = 60 in., e = 6 ft, and f = 10 ft.** - **83.1 ** **46. Determine the angle, β, and the length, s, of the two identical support links in Figure P3.6 when x = 150 mm and y = 275 mm.** - **28.6°** - **156.6 mm** **47. If the height, h, of the trailer shown in Figure P3.12 is 52 in., determine the length of ramp needed to maintain an angle, β, of 30°.** - **104 in. or 6 ft 4 in.** **48. Determine the total number of links.** - **L-10** - **J-13** **49. Determine the total number of joints.** - **L-6** - **J-7** **50. Determine the total number of links.** - **L-3** - **J-2 (LOWER PAIR)** - **J-1 (HIGHER PAIR)**