Work and Machines Reinforcement/Study Guide Name _____________key___________________ P:_____ Use the word bank below to match the key term with the best matching definition/description. Each key term is used once.
compound machine force Law of Conservation
of Energy Newton screw work
distance fulcrum lever resistance simple machine
effort inclined plane load pivot spring scale
energy inference moveable pulley plane wedge
fixed pulley input force movement pulley wheel and axle
Vocabulary Key Term Definition/Description
Law of Conservation of Energy 1. states that energy cannot be created or destroyed but only changes from one form to another
work 2. occurs when a force causes an object to move in the same direction that the force is applied
energy 3. ability to do work and make a change
movement 4. work requires effort and ___?____ over a distance
distance 5. work = Force x __________
effort 6. the force or energy you put into moving something
force 7. push or pull
fulcrum 8. pivot point of a lever
Resistance 9. force you overcome when using a simple machine (aka load, weight, output force)
input force 10. force you apply to a simple machine (aka effort force)
load 11. mass that is being moved
simple machine 12. device that multiplies your force or change the direction of the force
pivot 13. to turn or rotate
pulley 14. grooved wheel with a rope or cable wrapped over
lever 15. rigid bar or board that is free to rotate/pivot around a fulcrum
plane 16. flat surface
inclined plane 17. flat sloped surface (includes ramp, screw, wedge)
wheel and axle 18. two circular objects of different sizes that are attached and rotate together
wedge 19. two inclined planes joined back to back
screw 20. inclined plane wrapped around a cylinder, post, or shaft compound machine 21. when two or more simple machines work together
fixed pulley 22. pulley secured to a set point, changes the direction not force moveable pulley 23. pulley attached to the object moving and reduces effort force
spring scale 24. tool to measure force
Newton 25. metric SI unit that measures force
Label and Point to where the simple machines are located in each compound machine shown. (27-31) 27. Crane (3)
- wheel and axle -pulley: end -lever: arm
28. Can opener (3):
wedge, wheel and axle, lever (handles and turning knob)
29. Fishing Pole (4) Lever (pole, handle, reel release button), pulley (pole eyelet at
end), wheel and axle (reel), wedge (hook)
30. Apple Spiralizer (4): wheel and axle (handle), screw spiral, wedge (to pierce and slice), lever (suction at base)
31. Bicycle (3)
levers (handlebars, handbrakes, foot pedal), wheel and axles (handlebars, gears, wheels, pedals), pulley (chain and gears)
32. Identify the simple machines found in these common items. Items may have one or more simple machines. Use the abbreviations shown: lever (L), wheel and axle (W+A), Pulley (P), Inclined Plane-Ramp (R), Inclined Plane- Wedge (W), Inclined Plane-Screw (S)
airplane wing: W fork: W, L pliers: L stapler: L
arm: L funnel: S rake: L tongs: L
axe: W, L gears: W+A ramp: R toy cars: W+A
block-and-tackle: P (multiple)
hammer: L, W rock climbing gear: P tweezers: L boat bow (front): W jackhammer (digs into
cement):W, L
roller skates: W+A well and water bucket: P, W+A
bolt: S jar lid: S scissors: W, L wheel barrow: W+A, L
broom: L knife: W, L shoelaces: P wheelchair: W+A
door knob: W+A ladder: R shovel: W, L winding mountain
road: S
door stop: W lightbulb base: S snow plow: W, W+A, L window blinds: P elevator: P moving clothesline: P faucet spigot: W+A
escalator: P, R nail: W spiral staircase: S
BASEBALL BAT
Arm Lifting a Weight
34. Decide whether each situation is an example of work being done, label each as Yes or No.
Lifting a book Yes Carrying a box into a house No
Carrying a stack of books to another room No A weightlifter holding a weight above his head No
Running across a field Yes Sliding down a slide Yes
Jumping up to see over a fence Yes Pushing a sturdy wall that does not move No
Typing on a keyboard Yes Rolling a ball Yes
Holding a bag of groceries No Earth revolving around the Sun Yes
35. Which scenario below requires the least amount of effort force? _D_ Why? D-has wheels that reduce friction, ↓F,↑D
36. Label each pulley in A-D above as fixed (F) or moveable (M).
37. Which arrangement would require the least amount of effort force to lift the load? D-more pulleys 37. Which arrangement requires an effort force equal to the weight? A
38. How does pulley A make work easier? changes direction
39. You want to raise a flag 20 m into the air using a single fixed-pulley system. How far would you have to move the rope? 20 m
Effort
Effort
Fulcrum
Fulcrum
Load
Load
F
F
M F
M
40. Circle the diagram above that requires the least amount of force. Why?
-Ramp- ↓F↑D,
-fixed single pulley only changes direction, -lifting requires most effort
41. Each of the men in the illustration is pushing on the box. They each push for 30 seconds but do NOT move the box. The men applied force but
___work__ was not done.
42. We see evidence of energy when we see __work___ done. Work = Force x distance W=Fxd
Sample Problem: How much work is completed to lift a box 50 Newtons of force upward in 2 meters? W = F x d W= ?, F= 50 N, d= 2 m
W = (50N) x (2m) = 100Nm
43. If you wanted to do the same amount of work with less force (25 N), the distance moved would need to increase 4 m. W = 100 Nm, F = 25 N, d = ?
W = F x d = 100NM = 25N x ____. d= 4m 44. Work is performed by a lever when a load (L) of 5 Newtons is applied at one end.
a. Using the formula, what force (F) is required to make the lever balanced? (5N, 10N, 20N, 40N)
F = (5Nx4m)/(2m) = 10N b. How can the effort force be reduced (feels easier?) Move the fulcrum closer to the load, increase length of the effort side lever
45. Sam’s dad used a ramp to put a lawnmower in the back of his pickup truck. Sam’s dad said to him, “You see son, it takes a lot less work to use a ramp than to lift the lawnmower straight up from the ground.” What is wrong with the statement that Sam’s dad made? Takes less EFFORT not Work.
46. Which is the correct order for the technological design process?
A. Design a solution or product, implement the design, identify a problem or need, evaluate the solution or the product.
B. Identify a problem or need, design a solution or product, implement the design, evaluate the solution or the product.
C. Implement the design, identify a problem or a need, identify a problem or need, evaluate the solution or the product.
47. A company is designing a dam with a floodgate to keep houses safe during the rainy season. The company is reviewing several possible designs that have worked in the past (research) and is trying to develop a plan for implementing one design. Which is the next step in this process?
A. pick several dams to use in a consumer survey B. test each dam model during a different flood season
C. analyze the dam designs and pick one based on local needs
D. redesign the past dams based on what the company feels will work best
48. A factory is producing a new machine designed to reduce the amount of air pollution in houses. The machine was produced and sold to the public. After several months, reports show the machine is not working correctly. Which of these most likely caused this outcome?
A. The proper cost analysis was not performed.
B. The prototype was not tested before use by the public. C. The designers did not test other types of machines.
0.4 mL
49. Engineers plan to develop a new drill for use on oil rigs. What should the engineers do first in order to develop the new drill?
A. conduct research on features for the new drill C. determine the materials needed to build the new drill B. build a prototype of the new drill D. design a computer model of the new drill
50. Engineers designed a new construction material. When a strong enough force is applied to this material, the material turns red. This change in color is intended to warn people that the material has reached a breaking point. Which situation would best show that the new material provides a benefit?
A. In a laboratory test, the material fails to change color.
B. At a construction site, the color change allows workers to move to a safe area. C. When used in a building, the material changes colors in different levels of light. D. When used in a bridge, the material remains for a long time without changing color. 51. Which task is more suited for a human than a robot?
A. screwing in the same nuts on a wheel hubcap on an assembly line B. quality inspection for comfort and appearance
52. The first time a new device is built to be tested before final production by a company is called a(n)
__prototype_________________.
53. You want to build a model catapult complex machine. You want the catapult to be less than 2 cubic feet and to throw a ball. According to the engineering design process, which of the following should be your next step?
a. build/construct prototypes of different kinds of catapults b. gather the materials needed to build the catapult
c. research the different designs of catapults d. test the efficiency of the built catapult 51. a. What are the tools to the right called? graduated cylinders
b. SI metric unit? milliliters (mL)
c. Record the volume for each on the lines.
