Analysis
-
Review your lever graphs in Trial I.
Was the amount of force needed to lift the
potatoes in a first class lever different
when the sack was moved closer to the
rolling pin? Make a rule for lifting
objects with a first class lever that
includes how the force changes by moving the
load closer or further from the fulcrum.
-
How does the amount of force vary
between the fixed and moveable pulleys in
Trial II? Check out how many strings
"share" the load. Explain your results.
-
How did the force vary from lifting
the block straight up in the air to when it
was lifted on the ramp in Trial III? Think
about how far the wooden block must move
from the floor to the chair. Is it farther
to go straight up or with the inclined plane (ramp)?
-
The Mechanical Advantage (MA)
of a simple machine can be calculated based
on the measure of distance traveled by the
load, divided by the distance traveled by
the applied aorce. In the
case of an inclined plane, the ratio of
vertical height traveled divided by the
length of a ramp, is the MA for a
ramp MA = vertical
height/length of ramp
Determine the MA of your ramp.
-
Recall what you observed with the
levers and pulleys. Which rule would you
say is correct for an inclined plane (ramp)?
| a) Going up a ramp
to a given height, the longer the
ramp, the greater the effort. |
| b) Going up a ramp
to a given height, the longer the
ramp, the less the effort. |
| c) Going up a ramp
to a given height, it is the same
effort regardless of the length of
the ramp. |
-
Describe the benefits of using a
simple machine.
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