Download (8) Force, motion, and energy - 2010

(8) Force, motion, and energy. The student knows force and motion are related to potential and kinetic energy. The student is
expected to:
(E)
investigate how inclined planes and pulleys can be used to change the amount of force to move an object.
The amount of force is reduced, not the amount of work done. The force is spread out over a greater distance.
39. The diagrams illustrate the differences in the three types of levers. Which levers work
by changing the direction of the force so that the forces move in opposite directions?
6.8 E
A. only a first-class lever
B. a first-class lever and a second-class lever
C. a second-class lever and a third-class lever
D. only a second-class lever
40. A 400-N object is being lifted with a single movable pulley. Based on the type of
pulley system involved, you can conclude that the pulley is —
6.8 E
A. changing the direction of the effort force
B. changing the magnitude of the effort force
C. changing the direction and the magnitude of the effort force
D. multiplying the output force
41. Which of the following has a mechanical advantage of 2?
6.8 E
A. A single fixed pulley
B. A movable pulley
C. A pulley system, or block and tackle with three ropes
D. A pulley system made up of a single fixed pulley and a movable pulley with three ropes
42. The pliers shown above are a type of simple machine. They help make work easier by
—
6.8 E
A. increasing the applied force
B. changing the direction of the applied force
C. decreasing the effort applied
D. changing the speed of the applied force
43. Four inclined planes are shown. If you had to move a box that weighs 400 N a height
of 2 m off the ground, which inclined plane will allow you to accomplish this using the
least amount of force?
6.8 E
A. Inclined plane A
B. Inclined plane B
C. Inclined plane C
D. Inclined plane D
44. The drawing shows two simple machines. Both are examples of —
6.8 E
A. inclined planes
B. pulleys
C. levers
D. wheels and axles
45. How would moving the fulcrum closer to the person affect the action of the lever?
6.8 E
A. It changes the direction of the force that must be applied.
B. It would increase the output force.
C. It would require a greater input force to lift the rock.
D. It would decrease the input force needed to lift the rock.
6.8 E
46. How much force is needed to lift this object with the help of a pulley?
2.
A. a force equal to the force of the object
B. a force less than the force of the object
C. a force greater than the force of the object
D. zero force
(7.6A) A wheelbarrow can be used to more efficiently move a heavy
load. To which part of the wheelbarrow would the input force (effort)
be applied on this type of lever?
6.8 E
A
The Bucket
B
The Handles
C
The Legs
D
The Wheel
A
.
B
C
D
B
A
4.
6.8 E
(7.6A) Where was force applied to this lever to raise “B” up off the
ground?
A
B
C
D
“A” applied a downward force
“B” applied a downward force
“A” applied an upward force
“B” applied an upward force
10. (7.6A) Simple machines are useful because they:
A
B
increase kinetic energy
change the amount or direction of force to make work feel
easier
C
make the potential energy zero
D
eliminate the need to do work
12.
6.8 E
(7.6A) A student wishes to lift a heavy load with a pulley.
Which pulley arrangement would make this job the
easiest?
A
5N
B
5N
C
5N
D
5N
Force
Load
13. (7.6A) the diagram above illustrates a movable pulley. This pulley gives a
mechanical advantage by A
B
C
D
reducing the force required to lift the load.
changing the force direction
requiring the force to be greater than the load
requiring the force to move less distance than the load
23. (7.6A) The diagrams illustrate how a screwdriver can be used to pry
off the lid of a paint can. The arrows in the diagrams represent input
force and output force. The width of the arrows indicates the relative
amount of force and the length of the arrows indicates the distance
through which the force moves. The correct diagram is:
A
6.8 E
C
B
D
24. (7.6A) Which of the following describes the use of mechanical
advantage?
6.8 E
a. Gerald pushes a 1200N refrigerator across the kitchen floor.
b. Sarah pulls on a wagon wheel that won’t budge
c. Tammy pulls with 15N of force on a lever to lift a 120N box.
d. Steve uses an electric mixer to make cake batter
6.8 E
25. (7.6A) Which of the simple machines below would provide you the
greatest mechanical advantage?
Simple Machine
Lever 1
Weight of Object
6.5N
Force required to lift
object
1N
Pulley 1
Pulley 2
Lever 2
14N
144N
24N
14N
24N
3N
A lever 1
B pulley 1
C pulley 2
D lever 2
17.
6.8 E
( 7.6A) The picture shows a simple fixed pulley being used to lift
a heavy box. Which of these does the pulley change?
A The mass of the box being moved
B
The amount of force required to move the box
C
The direction of force required to move the box
D The amount of energy required to move the box