# Mechanical Engineering

Subject : engineering
Instructions:
• Answer 50 questions in 15 minutes.
• If you are not ready to take this test, you can study here.
• Match each statement with the correct term.
• Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Combustion of fuel mixture ignited by spark plug

2. A device that uses energy to do work to accomplish some desired activity - They do not produce energy - but they do transmit and transform energy - Machines can transmit a force - control its motion - and change its direction - a system of components

3. Rotation will not occur - but translation might occur

4. Applied at an angle or parallel to a surface

5. Length / Time

6. Weight/Time

7. When the work done by the effort just equals the work done by the load - ______ of the machine will occur

8. Varies by location (on earth) - distance (from earth) - and mass (of planet)

9. The perpendicular distance from the pivot point to the point of application of the force (d) - M=Fd -Clockwise=Negative moment -Counterclockwise=Positive moment

10. A pull on an object

11. What we are not studying

12. Describes how applied forces bring a body into rest or equilibrium

13. In a right triangle - the sum of the squares of the sides equals the square of the hypotenous

14. Modern Technology- More efficient-Better Cooling-Easier to service- longer life - lither weight- More expensive

15. A system adopted from an old British system of units in the 13th century -Engineering system -Units: length- foot (ft) - time- second (s) - force-(lbs) - Mass is a derived unit called a slug -Political/Economic choice -Awkward

16. Used in cars -2 rotations of crankshaft -4 strokes (down - up - down - up) of piston - i.e. cars - trucks - planes - buses - motorcycles - submarine -1% of gas actually moves people

17. Every object continues in motion in a straight line unless acted upon by some force -Every object at rest continues at rest unless acted upon by a force -So forces cause a change in an object's state of motion

18. Energy may enter or leave. Mass can enter or leave the system i.e. open water bottle - molecule - hydraulic cylinder - human

19. 1. Magnitude: size - a numberi.e. 50 mph 2. Direction: angle i.e. N -E -W -S

20. Pistons connected to crankshaft -1 stroke up - 1 stroke down of the piston -1 rotation of the piston -Problems: high emissions - noisy - inefficient - high vibrations - unburnt fuel - burnt oil -Benefits: small and light -Being phased out in USA - i.

21. A change in velocity over time -Unites: USA- ft/s^2 and SI: m/s^2

22. Liquid or gas

23. When the moving fluid is a gas

24. Combustion ignited by spark plug and materials are compressed

25. A small piece that makes up a larger whole. Each component is there for a specific job - but the sum of components

26. Air is drawn in

27. A movement around a central pivot point (rotational movement) -Units: revolutions per second (rps) and revolutions per minute (rpm)

28. Brake pedal and linkage - Master Cylinder - Wheel cylinders (4) - Hydraulic lines - Hydraulic fluid - Mechanical advantage is provided by the foot pedal to the booster (level) - A greater force is applied on the wheel cylinders than on the brake peda

29. Piston travels up and exhaust valve opens. Combustion by product exhaustion

30. Force without machine/Force with machine

31. When a simple machine increases a force it is at the expense of a ____ in the distance the load is moved

32. For every action there is an equal and opposite reaction -Force -F=mg -Earth exerts a force on all of us

33. The magnitude of something in a particular direction

34. Can be applied:-By direct contact: push - pull - twist -At a distance: gravity - magnetism Can change: speed - direction - shape - units of force

35. When two parallel forces equal in magnitude and opposite direction - i.e. steering wheel - turn a know - turn on and off a faucet

36. Exhaust of combustion products

37. The designing of machines that contribute to society and our quality of life - Mechanical engineers apply the principles of mathematics - chemistry - and physics to solve real- world problems

38. Intake of fuel and air mixture - compression of mixture by piston

39. Mechanics is an application of math that describes how forces affect a body

40. Air is compressed - work is done on the system

41. External Combustion engine -Only used in factories and plants (not used in cars)

42. Derived from - or composed of - base dimensions i.e. Area (length x width) - Weight (mass x acceleration) - velocity (length/time)

43. When the sum of all forces and the sum of all moments both equal forces - No movement

44. A^2+b^2=c^2

45. If the force needed to operate the machine (input force) is less than the force being opposed or the load being moved (output force) -The ratio of the output force divided by the input force -If the number is greater than one - there is a mechanical

46. An application of Pascal's Principle (trading distance and force while doing the same amount of work) -Gives a mechanical advantage -The muscles of machines - used to produce very large forces - use a fluid under pressure (gas is low pressure and liq

47. Can be applied at a time on an object

48. The force simple machines use to do work on a single load or against a single force

49. Work/force or vertical distance/sloping distance

50. More compact (size of beer keg) - No valves -Benefits: fewer parts - lower engine weight Problems: seal - lower inertia forces -1 rotar=3 to 4 pistons